@inproceedings{BBS-forte06, address = {Paris, France}, month = sep, year = 2006, volume = 4229, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Najm, Elie and Pradat{-}Peyre, Jean-Fran{\c{c}}ois and Vigui{\'e} Donzeau-Gouge, V{\'e}ronique}, acronym = {{FORTE}'06}, booktitle = {{P}roceedings of 26th {IFIP} {WG6.1} {I}nternational {C}onference on {F}ormal {T}echniques for {N}etworked and {D}istributed {S}ystems ({FORTE}'06)}, author = {Baier, Christel and Bertrand, Nathalie and Schnoebelen, {\relax Ph}ilippe}, title = {Symbolic verification of communicating systems with probabilistic message losses: liveness and fairness}, pages = {212-227}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BBS-forte06.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BBS-forte06.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/BBS-forte06.ps}, doi = {10.1007/11888116_17}, abstract = {NPLCS's are a new model for nondeterministic channel systems where unreliable communication is modeled by probabilistic message losses. We~show that, for \(\omega\)-regular linear-time properties and finite-memory schedulers, qualitative model-checking is decidable. The~techniques extend smoothly to questions where fairness restrictions are imposed on the schedulers. The~symbolic procedure underlying our decidability proofs has been implemented and used to study a simple protocol handling two-way transfers in an unreliable setting.} }

@inproceedings{BLP-cav06, address = {Seattle, Washington, USA}, month = aug, year = 2006, volume = 4144, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Ball, {\relax Th}omas and Jones, Robert B.}, acronym = {{CAV}'06}, booktitle = {{P}roceedings of the 18th {I}nternational {C}onference on {C}omputer {A}ided {V}erification ({CAV}'06)}, author = {Bardin, S{\'e}bastien and Leroux, J{\'e}r{\^o}me and Point, G{\'e}rald}, title = {{FAST} {E}xtended {R}elease}, pages = {63-66}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BLP-cav06.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BLP-cav06.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/BLP-cav06.ps}, doi = {10.1007/11817963_9}, abstract = {{\scshape Fast} is a tool designed for the analysis of counter systems, \emph{i.e.}~automata extended with unbounded integer variables. Despite the reachability set is not recursive in general, Fast implements several innovative techniques such as acceleration and circuit selection to solve this problem in practice. In its latest version, the tool is built upon an open architecture: the Presburger library is manipulated through a clear and convenient interface, thus any Presburger arithmetics package can be plugged to the tool. We provide four implementations of the interface using Lash, Mona, Omega and a new shared automata package with computation cache. Finally new features are available, like different acceleration algorithms.} }

@inproceedings{BFLS-avis06, address = {Vienna, Austria}, month = apr, year = 2006, editor = {Bharadwaj, Ramesh}, acronym = {{AVIS}'06}, booktitle = {{P}roceedings of the 5th {I}nternational {W}orkshop on {A}utomated {V}erification of {I}nfinite-{S}tate {S}ystems ({AVIS}'06)}, author = {Bardin, S{\'e}bastien and Finkel, Alain and Lozes, {\'E}tienne and Sangnier, Arnaud}, title = {From Pointer Systems to Counter Systems Using Shape Analysis}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFLS-AVIS-06.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFLS-AVIS-06.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/BFLS-AVIS-06.ps}, abstract = {We aim at checking safety properties on systems manipulating dynamic linked lists. First we prove that every pointer system is bisimilar to an effectively constructible counter system. We then deduce a two-step analysis procedure. We first build an over-approximation of the reachability set of the pointer system. If this over-approximation is too coarse to conclude, we then extract from it a bisimilar counter system which is analyzed via efficient symbolic techniques developed for general counter systems.} }

@inproceedings{BBS-lpar06, address = {Phnom Penh, Cambodia}, month = nov, year = 2006, volume = 4246, series = {Lecture Notes in Artificial Intelligence}, publisher = {Springer}, editor = {Hermann, Miki and Voronkov, Andrei}, acronym = {{LPAR}'06}, booktitle = {{P}roceedings of the 13th {I}nternational {C}onference on {L}ogic for {P}rogramming, {A}rtificial {I}ntelligence, and {R}easoning ({LPAR}'06)}, author = {Baier, Christel and Bertrand, Nathalie and Schnoebelen, {\relax Ph}ilippe}, title = {On Computing Fixpoints in Well-Structured Regular Model Checking, with Applications to Lossy Channel Systems}, pages = {347-361}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BBS-lpar06.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BBS-lpar06.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/BBS-lpar06.ps}, doi = {10.1007/11916277_24}, abstract = {We prove a general finite convergence theorem for {"}upward-guarded{"} fixpoint expressions over a well-quasi-ordered~set. This has immediate applications in regular model checking of well-structured systems, where a main issue is the eventual convergence of fixpoint computations. In~particular, we are able to directly obtain several new decidability results on lossy channel systems.} }

@article{BBS-ipl05, publisher = {Elsevier Science Publishers}, journal = {Information Processing Letters}, author = {Baier, Christel and Bertrand, Nathalie and Schnoebelen, {\relax Ph}ilippe}, title = {A note on the attractor-property of infinite-state {M}arkov chains}, year = 2006, month = jan, number = 2, volume = 97, pages = {58-63}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/IPL-BBS.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/IPL-BBS.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/IPL-BBS.ps}, doi = {10.1016/j.ipl.2005.09.011}, abstract = {In the past five years, a series of verification algorithms has been proposed for infinite Markov chains that have a finite attractor, \emph{i.e.}, a set that will be visited infinitely often almost surely starting from any state. \par In this paper, we establish a sufficient criterion for the existence of an attractor. We show that if the states of a Markov chain can be given levels (positive integers) such that the expected next level for states at some level \(n > 0\) is less than \(n-\Delta\) for some positive \(\Delta\), then the states at level~\(0\) constitute an attractor for the chain. As an application, we obtain a direct proof that some probabilistic channel systems combining message losses with duplication and insertion errors have a finite attractor.} }

@inproceedings{BS05-express, address = {San Francisco, California, USA}, month = jul, year = 2006, number = 3, volume = 154, series = {Electronic Notes in Theoretical Computer Science}, publisher = {Elsevier Science Publishers}, editor = {Baeten, Jos and Phillips, Iain}, acronym = {{EXPRESS}'05}, booktitle = {{P}roceedings of the 12th {I}nternational {W}orkshop on {E}xpressiveness in {C}oncurrency ({EXPRESS}'05)}, author = {Bertrand, Nathalie and Schnoebelen, {\relax Ph}ilippe}, title = {A short visit to the {STS} hierarchy}, pages = {59-69}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BS05-express.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BS05-express.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/BS05-express.ps}, doi = {10.1016/j.entcs.2006.05.007}, abstract = {The hierarchy of Symbolic Transition Systems, introduced by Henzinger, Majumdar and Raskin, is an elegant classification tool for some families of infinite-state operational models that support some variants of a symbolic {"}backward closure{"} verification algorithm. It was first used and illustrated with families of hybrid systems.\par In this paper we investigate whether the STS hierarchy can account for classical families of infinite-state systems outside of timed or hybrid systems.} }

@inproceedings{DDFG-atva06, address = {Beijing, China}, month = oct, year = {2006}, volume = 4218, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Graf, Susanne and Zhang, Wenhui}, acronym = {{ATVA}'06}, booktitle = {{P}roceedings of the 4th {I}nternational {S}ymposium on {A}utomated {T}echnology for {V}erification and {A}nalysis ({ATVA}'06)}, author = {Demri, St{\'e}phane and Finkel, Alain and Goranko, Valentin and van Drimmelen, Govert}, title = {Towards a model-checker for counter systems}, pages = {493-507}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DDFG-atva06.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DDFG-atva06.pdf}, doi = {10.1007/11901914_36}, abstract = {This paper deals with model-checking of fragments and extensions of~\(\mathrm{CTL}^{*}\) on infinite-state Presburger counter systems, where the states are vectors of integers and the transitions are determined by means of relations definable within Presburger arithmetic. We have identified a natural class of admissible counter systems~(ACS) for which we show that the quantification over paths in~\(\mathrm{CTL}^{*}\) can be simulated by quantification over tuples of natural numbers, eventually allowing translation of the whole Presburger-\(\mathrm{CTL}^{*}\) into Presburger arithmetic, thereby enabling effective model checking. We have provided evidence that our results are close to optimal with respect to the class of counter systems described above. Finally, we design a complete semi-algorithm to verify first-order~\(\mathrm{LTL}\) properties over trace-flattable counter systems, extending the previous underlying FAST semi-algorithm to verify reachability questions over flattable counter systems. } }

@article{FGRV-tcs05, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Finkel, Alain and Geeraerts, Gilles and Raskin, Jean-Fran{\c{c}}ois and Van{~}Begin, Laurent}, title = {On the \(\omega\)-Language Expressive Power of Extended {P}etri Nets}, year = 2006, month = may, volume = 356, number = 3, pages = {374-386}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FGRV-TCS04.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FGRV-TCS04.pdf}, doi = {10.1016/j.tcs.2006.02.008}, abstract = {In this paper, we study the expressive power of several monotonic extensions of Petri nets. We compare the expressive power of Petri nets, Petri nets extended with \emph{non-blocking arcs} and Petri nets extended with \emph{transfer arcs}, in terms of \(\omega\)-languages. We show that the hierarchy of expressive powers of those models is strict. To prove these results, we propose \emph{original techniques} that rely on well-quasi orderings and monotonicity properties.} }

@article{KucSch-TCS, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Ku{\v c}era, Anton{\'\i}n and Schnoebelen, {\relax Ph}ilippe}, title = {A General Approach to Comparing Infinite-State Systems with Their Finite-State Specifications}, number = {2-3}, volume = {358}, pages = {315-333}, month = aug, year = 2006, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/KucSch-TCS.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/KucSch-TCS.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/KucSch-TCS.ps}, doi = {10.1016/j.tcs.2006.01.021}, abstract = {We introduce a generic family of behavioral relations for which the regular equivalence problem (\emph{i.e.}, comparing an arbitrary transition system to some finite-state specification) can be reduced to the model checking problem against simple modal formulae. As an application, we derive decidability of several regular equivalence problems for well-known families of infinite-state systems. } }

@phdthesis{THESE-bertrand06, author = {Bertrand, Nathalie}, title = {Mod{\`e}les stochastiques pour les pertes de messages dans les protocoles asynchrones et techniques de v{\'e}rification automatique}, year = 2006, month = oct, type = {Th{\`e}se de doctorat}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/these-bertrand.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/these-bertrand.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/these-bertrand.ps} }

@mastersthesis{brochenin-master, author = {Brochenin, R{\'e}mi}, title = {Techniques d'automates pour raisonner sur la m{\'e}moire}, school = {{M}aster {R}echerche {I}nformatique de {L}yon~--- {I}nformatique {F}ondamentale, Lyon, France}, type = {Rapport de {M}aster}, month = jun, year = 2006, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/Brochenin-M2.ps}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/Brochenin-M2.ps} }

@inproceedings{HIV-fossacs08, address = {Budapest, Hungary}, month = mar # {-} # apr, year = 2008, volume = 4962, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Amadio, Roberto}, acronym = {{FoSSaCS}'08}, booktitle = {{P}roceedings of the 11th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'08)}, author = {Habermehl, Peter and Iosif, Radu and Vojnar, Tom{\'a}{\v{s}}}, title = {What else is decidable about arrays?}, pages = {474-489}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/hiv07-TR.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/hiv07-TR.pdf}, doi = {10.1007/978-3-540-78499-9_33}, abstract = {We introduce a new decidable logic for reasoning about infinite arrays of integers. The logic is in the \(\exists^{*}\forall^{*}\) first-order fragment and allows (1)~Presburger constraints on existentially quantified variables, (2)~difference constraints as well as periodicity constraints on universally quantified indices, and (3)~difference constraints on values. In~particular, using our logic, one can express constraints on consecutive elements of arrays (\emph{e.g.}~\(\forall i.\ 0 \leq i < n \rightarrow a[i + 1] = a[i] - 1\)) as well as periodic facts (\emph{e.g.}~\(\forall i.\ i \equiv_2 0 \rightarrow a[i] = 0\)). The decision procedure follows the automata-theoretic approach: we~translate formulae into a special class of B{\"u}chi counter automata such that any model of a formula corresponds to an accepting run of the automaton, and vice versa. The~emptiness problem for this class of counter automata is shown to be decidable, as a consequence of earlier results on counter automata with a flat control structure and transitions based on difference constraints. We~show interesting program properties expressible in our logic, and give an example of invariant verification for programs that handle integer arrays.} }

@inproceedings{CS-fossacs08, address = {Budapest, Hungary}, month = mar # {-} # apr, year = 2008, volume = 4962, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Amadio, Roberto}, acronym = {{FoSSaCS}'08}, booktitle = {{P}roceedings of the 11th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'08)}, author = {Chambart, Pierre and Schnoebelen, {\relax Ph}ilippe}, title = {The \(\omega\)-Regular {P}ost Embedding Problem}, pages = {97-111}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CS-fossacs08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CS-fossacs08.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/CS-fossacs08.ps}, doi = {10.1007/978-3-540-78499-9_8}, abstract = {Post's Embedding Problem is a new variant of Post's Correspondence Problem where words are compared with embedding rather than equality. It~has been shown recently that adding regular constraints on the form of admissible solutions makes the problem highly non-trivial, and relevant to the study of lossy channel systems. Here we consider the infinitary version and its application to recurrent reachability in lossy channel systems.} }

@mastersthesis{chambart-master, author = {Chambart, Pierre}, title = {Canaux fiables et non-fiables~: fronti{\`e}res de la d{\'e}cidabilit{\'e}}, school = {{M}aster {P}arisien de {R}echerche en {I}nformatique, Paris, France}, type = {Rapport de {M}aster}, year = 2007, month = sep, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/chambart-m2.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/chambart-m2.pdf} }

@inproceedings{BMOSW-stacs08, address = {Bordeaux, France}, month = feb, year = 2008, volume = 1, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Albers, Susanne and Weil, Pascal}, acronym = {{STACS}'08}, booktitle = {{P}roceedings of the 25th {A}nnual {S}ymposium on {T}heoretical {A}spects of {C}omputer {S}cience ({STACS}'08)}, author = {Bouyer, Patricia and Markey, Nicolas and Ouaknine, Jo{\"e}l and Schnoebelen, {\relax Ph}ilippe and Worrell, James}, title = {On Termination for Faulty Channel Machines}, pages = {121-132}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/bmosw-stacs08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/bmosw-stacs08.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/bmosw-stacs08.ps}, abstract = {A channel machine consists of a finite controller together with several fifo channels; the controller can read messages from the head of a channel and write messages to the tail of a channel. In this paper, we focus on channel machines with \emph{insertion errors}, \textit{i.e.}, machines in whose channels messages can spontaneously appear. Such devices have been previously introduced in the study of Metric Temporal Logic. We~consider the termination problem: are all the computations of a given insertion channel machine finite? We~show that this problem has non-elementary, yet primitive recursive complexity.} }

@inproceedings{FLS-ilc07, address = {Cape Town, South Africa}, month = oct, year = 2009, volume = 5489, series = {Lecture Notes in Artificial Intelligence}, publisher = {Springer-Verlag}, editor = {Archibald, Margaret and Brattka, Vasco and Goranko, Valentin and L{\"o}we, Benedikt}, acronym = {{ILC}'07}, booktitle = {{R}evised {S}elected {P}apers of the {I}nternational {C}onference on {I}nfinity in {L}ogic {\&} {C}omputation ({ILC}'07)}, author = {Finkel, Alain and Lozes, {\'E}tienne and Sangnier, Arnaud}, title = {Towards Model Checking Pointer Systems}, pages = {56-82}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FLS-ilc07.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FLS-ilc07.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/FLS-ilc07.ps}, doi = {10.1007/978-3-642-03092-5_6}, abstract = {We aim at checking safety and temporal properties over models representing the behavior of programs manipulating dynamic singly-linked lists. The properties we consider not only allow to perform a classical shape analysis, but we also want to check quantitative aspect on the manipulated memory heap. We first explain how a translation of programs into counter systems can be used to check safety problems and temporal properties. We then study the decidability of these two problems considering some restricted classes of programs, namely flat programs without destructive update. We obtain the following results: (1)~the model-checking problem is decidable if the considered program works over acyclic lists; (2)~the safety problem is decidable for programs without alias test. We finally explain the limit of our decidability results, showing that relaxing one of the hypothesis leads to undecidability results.} }

@inproceedings{EF-infinity07, optaddress = {Lisbon, Portugal}, month = jul, year = 2009, volume = 239, series = {Electronic Notes in Theoretical Computer Science}, publisher = {Elsevier Science Publishers}, realeditor = {Madhusudan, P. and Kahlon, Vineet}, editor = {Habermehl, Peter and Vojnar, Tom{\'a}{\v{s}}}, acronym = {{INFINITY}'06,'07,'08}, booktitle = {{J}oint {P}roceedings of the 8th, 9th and 10th {I}nternational {W}orkshops on {V}erification of {I}nfinite {S}tate {S}ystems ({INFINITY}'06,'07,'08)}, author = {Encrenaz, Emmanuelle and Finkel, Alain}, title = {Automatic verification of counter systems with ranking functions}, pages = {85-103}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/EF-infinity07.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/EF-infinity07.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/EF-infinity07.ps}, doi = {10.1016/j.entcs.2009.05.032}, abstract = {The verification of final termination for counter systems is undecidable. For non flattable counter systems, the verification of this type of property is generally based on the exhibition of a ranking function. Proving the existence of a ranking function for general counter systems is also undecidable. We~provide a framework in which the verification whether a given function is a ranking function is decidable. This framework is applicable to convex counter systems which admit a Presburger or a LPDS ranking function. This extends the results of [A.~Bradley, Z.~Manna, and B.~Sipma. \textit{Termination analysis of integer linear loops}. In~CONCUR'05, LNCS~3653, p.~488-502. Springer]. From this framework, we derive a model-checking algorithm to verify whether a final termination property is satisfied or not. This approach has been successfully applied to the verification of a parametric version of the ZCSP protocol.} }

@mastersthesis{villard-master, author = {Villard, Jules}, title = {Logique spatiale pour le pi-calcul appliqu{\'e}}, school = {{M}aster {P}arisien de {R}echerche en {I}nformatique, Paris, France}, type = {Rapport de {M}aster}, year = 2007, month = sep, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/villard-m2.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/villard-m2.pdf} }

@inproceedings{HIRV-atva2007, address = {Tokyo, Japan}, month = oct, year = {2007}, volume = 4762, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Namjoshi, Kedar and Yoneda, Tomohiro}, acronym = {{ATVA}'07}, booktitle = {{P}roceedings of the 5th {I}nternational {S}ymposium on {A}utomated {T}echnology for {V}erification and {A}nalysis ({ATVA}'07)}, author = {Habermehl, Peter and Iosif, Radu and Rogalewicz, Adam and Vojnar, Tom{\'a}{\v{s}}}, title = {Proving Termination of Tree Manipulating Programs}, pages = {145-161}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/HIRV-atva07.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/HIRV-atva07.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/HIRV-atva07.ps}, doi = {10.1007/978-3-540-75596-8_12}, abstract = {We consider the termination problem of programs manipulating tree-like dynamic data structures. Our~approach is based on a counter-example guided abstraction refinement loop. We use abstract regular tree model-checking to infer invariants of the program. Then, we~translate the program to a counter automaton~(CA) which simulates~it. If~the CA can be shown to terminate using existing techniques, the~program terminates. If~not, we analyse the possible counterexample given by a~CA termination checker and either conclude that the program does not terminate, or else refine the abstraction and repeat. We~show that the spuriousness problem for lasso-shaped counterexamples is decidable in some non-trivial cases. We~applied the method successfully on several interesting case studies. } }

@inproceedings{BHJS-fct07, address = {Budapest, Hungary}, month = aug, year = 2007, volume = 4639, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Csuhaj-Varj{\'u}, Erzs{\'e}bet and {\'E}sik, Zolt{\'a}n}, acronym = {{FCT}'07}, booktitle = {{P}roceedings of the 16th {I}nternational {S}ymposium on {F}undamentals of {C}omputation {T}heory ({FCT}'07)}, author = {Bouajjani, Ahmed and Habermehl, Peter and Jurski, Yan and Sighireanu, Mihaela}, title = {Rewriting Systems with Data~-- {A} Framework for Reasoning About Systems with Unbounded Structures over Infinite Data Domains}, pages = {1-22}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BHJS-fct07.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BHJS-fct07.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/BHJS-fct07.ps}, doi = {10.1007/978-3-540-74240-1_1}, abstract = {We introduce a uniform framework for reasoning about infinite-state systems with unbounded control structures and unbounded data domains. Our~framework is based on constrained rewriting systems on words over an infinite alphabet. We~consider several rewriting semantics: factor, prefix, and multiset rewriting. Constraints are expressed in a logic on such words which is parametrized by a first-order theory on the considered data domain. We show that our framework is suitable for reasoning about various classes of systems such as recursive sequential programs, multithreaded programs, parametrized and dynamic networks of processes,~etc. Then, we provide generic results (1)~for the decidability of the satisfiability problem of the fragment of this logic provided that the underlying logic on data is decidable, and (2)~for proving inductive invariance and for carrying out Hoare style reasoning within this fragment. We also show that the reachability problem if decidable for a class of prefix rewriting systems with integer data.} }

@inproceedings{CS-fsttcs07, address = {New~Delhi, India}, month = dec, year = 2007, volume = 4855, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Arvind, V. and Prasad, Sanjiva}, acronym = {{FSTTCS}'07}, booktitle = {{P}roceedings of the 27th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'07)}, author = {Chambart, Pierre and Schnoebelen, {\relax Ph}ilippe}, title = {{P}ost Embedding Problem is not Primitive Recursive, with Applications to Channel Systems}, pages = {265-276}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CS-fsttcs07.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CS-fsttcs07.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/CS-fsttcs07.ps}, doi = {10.1007/978-3-540-77050-3_22}, abstract = {We introduce \textsf{PEP}, the Post Embedding Problem, a variant of \textsf{PCP} where one compares strings with the subword relation, and \textsf{PEP}\textsuperscript{reg}, a further variant where solutions are constrained and must belong to a given regular language. \textsf{PEP}\textsuperscript{reg} is decidable but not primitive recursive. This entails the decidability of reachability for unidirectional systems with one reliable and one lossy channel. } }

@inproceedings{DR-lpar07, address = {Yerevan, Armenia}, month = oct, year = 2007, volume = 4790, series = {Lecture Notes in Artificial Intelligence}, publisher = {Springer}, editor = {Dershowitz, Nachum and Voronkov, Andrei}, acronym = {{LPAR}'07}, booktitle = {{P}roceedings of the 14th {I}nternational {C}onference on {L}ogic for {P}rogramming, {A}rtificial {I}ntelligence, and {R}easoning ({LPAR}'07)}, author = {Demri, St{\'e}phane and Rabinovich, Alexander}, title = {The complexity of temporal logic with until and since over ordinals}, pages = {531-545}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DR-lpar07.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DR-lpar07.pdf}, doi = {10.1007/978-3-540-75560-9_38}, abstract = {We consider the temporal logic with since and until modalities. This temporal logic is expressively equivalent over the class of ordinals to first-order logic thanks to Kamp's theorem. We~show that it has a PSPACE-complete satisfiability problem over the class of ordinals. Among the consequences of our proof, we show that given the code of some countable ordinal~\(\alpha\) and a formula, we can decide in PSPACE whether the formula has a model over~\(\alpha\). In~order to show these results, we~introduce a class of simple ordinal automata, as expressive as B{\"u}chi ordinal automata. The PSPACE upper bound for the satisfiability problem of the temporal logic is obtained through a reduction to the nonemptiness problem for the simple ordinal automata.} }

@misc{persee-final, author = {Schnoebelen, {\relax Ph}ilippe and Bouajjani, Ahmed and Sutre, Gr{\'e}goire}, title = {{ACI} {S}{\'e}curit{\'e} {I}nformatique {PERS{\'E}E}~--- Rapport final}, year = 2006, month = nov, type = {Contract Report}, note = {12~pages}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/Persee-final.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/Persee-final.pdf} }

@inproceedings{BDL-hav07, address = {Braga, Portugal}, month = mar, year = 2007, editor = {Berdine, Josh and Sagiv, Mooly}, acronym = {{HAV}'07}, booktitle = {{P}roceedings of the 1st {W}orkshop on {H}eap {A}nalysis and {V}erification ({HAV}'07)}, author = {Brochenin, R{\'e}mi and Demri, St{\'e}phane and Lozes, {\'E}tienne}, title = {Reasoning about Sequences of Memory States}, preliminary-version-of = {BDL-lfcs2007}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BDL-hav07.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BDL-hav07.pdf}, abstract = {In order to verify programs with pointer variables, we introduce a temporal logic LTL\textsuperscript{mem} whose underlying assertion language is the quantifier-free fragment of separation logic and the temporal logic on the top of it is the standard linear-time temporal logic~LTL. We~state the complexity of various model-checking and satisfiability problems for LTL\textsuperscript{mem} , considering various fragments of separation logic (including pointer arithmetic), various classes of models (with or without constant heap), and the influence of fixing the initial memory state. Our main decidability result is PSPACE-completeness of the satisfiability problems on the record fragment and on a classical fragment allowing pointer arithmetic. \(\Sigma^{0}_{1}\)-completeness or \(\Sigma^{1}_{1}\)-completeness results are established for various problems, and underline the tightness of our decidability results.} }

@article{BBS-arxiv05, publisher = {ACM Press}, journal = {ACM Transactions on Computational Logic}, author = {Baier, Christel and Bertrand, Nathalie and Schnoebelen, {\relax Ph}ilippe}, title = {Verifying nondeterministic probabilistic channel systems against {{\(\omega\)}}-regular linear-time properties}, year = 2007, volume = 9, number = 1, nopages = {}, month = dec, url = {http://arxiv.org/abs/cs.LO/0511023}, pdf = {http://arxiv.org/pdf/cs.LO/0511023}, ps = {http://arxiv.org/ps/cs.LO/0511023}, doi = {10.1145/1297658.1297663}, abstract = {Lossy channel systems (LCS's) are systems of finite state processes that communicate via unreliable unbounded fifo channels. We introduce NPLCS's, a variant of LCS's where message losses have a probabilistic behavior while the component processes behave nondeterministically, and study the decidability of qualitative verification problems for \(\omega\)-regular linear-time properties.\par We show that ---in contrast to finite-state Markov decision processes--- the satisfaction relation for linear-time formulas depends on the type of schedulers that resolve the nondeterminism. While the qualitative model checking problems for the full class of history-dependent schedulers is undecidable, the same questions for finite-memory schedulers can be solved algorithmically. Additionally, some special kinds of reachability, or recurrent reachability, qualitative properties yield decidable verification problems for the full class of schedulers, which ---for this restricted class of problems--- are as powerful as finite-memory schedulers, or even a subclass of them.} }

@phdthesis{sangnier-these2008, author = {Sangnier, Arnaud}, title = {V{\'e}rification de syst{\`e}mes avec compteurs et pointeurs}, year = 2008, month = nov, type = {Th{\`e}se de doctorat}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/these-AS07.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/these-AS07.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/these-AS07.ps} }

@inproceedings{BFS-infinity08, optaddress = {Toronto, Canada}, month = jul, year = 2009, volume = 239, series = {Electronic Notes in Theoretical Computer Science}, publisher = {Elsevier Science Publishers}, editor = {Habermehl, Peter and Vojnar, Tom{\'a}{\v{s}}}, acronym = {{INFINITY}'06,'07,'08}, booktitle = {{J}oint {P}roceedings of the 8th, 9th and 10th {I}nternational {W}orkshops on {V}erification of {I}nfinite {S}tate {S}ystems ({INFINITY}'06,'07,'08)}, author = {Bouchy, Florent and Finkel, Alain and Sangnier, Arnaud}, title = {Reachability in Timed Counter Systems}, pages = {167-178}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFS-infinity08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFS-infinity08.pdf}, doi = {10.1016/j.entcs.2009.05.038}, abstract = {We introduce Timed Counter Systems, a~new class of systems mixing clocks and counters. Such systems have an infinite state space, hence their reachability problems are undecidable. By~abstracting clock values with a Region Graph, we~show the Counter Reachability Problem to be decidable for three subclasses: Timed~VASS, Bounded Timed Counter Systems, and Reversal-Bounded Timed Counter Systems.} }

@proceedings{HV-infinity2008, title = {{J}oint {P}roceedings of the 8th, 9th and 10th {I}nternational {W}orkshops on {V}erification of {I}nfinite {S}tate {S}ystems ({INFINITY}'06,'07,'08)}, booktitle = {{J}oint {P}roceedings of the 8th, 9th and 10th {I}nternational {W}orkshops on {V}erification of {I}nfinite {S}tate {S}ystems ({INFINITY}'06,'07,'08)}, optacronym = {{INFINITY}'06,'07,'08}, editor = {Habermehl, Peter and Vojnar, Tom{\'a}{\v{s}}}, publisher = {Elsevier Science Publishers}, doi = {10.1016/j.entcs.2009.05.026}, series = {Electronic Notes in Theoretical Computer Science}, volume = 239, year = 2009, month = jul, optaddress = {Toronto, Canada} }

@inproceedings{CS-concur08, address = {Toronto, Canada}, month = aug, year = 2008, volume = 5201, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {van Breugel, Franck and Chechik, Marsha}, acronym = {{CONCUR}'08}, booktitle = {{P}roceedings of the 19th {I}nternational {C}onference on {C}oncurrency {T}heory ({CONCUR}'08)}, author = {Chambart, Pierre and Schnoebelen, {\relax Ph}ilippe}, title = {Mixing Lossy and Perfect Fifo Channels}, pages = {340-355}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CS-concur08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CS-concur08.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/CS-concur08.ps}, doi = {10.1007/978-3-540-85361-9_28}, abstract = {We~consider asynchronous networks of finite-state systems communicating \emph{via} a combination of reliable and lossy fifo channels. Depending on the topology, the~reachability problem for such networks may be decidable. We~provide a complete classification of network topologies according to whether they lead to a decidable reachability problem. Furthermore, this classification can be decided in polynomial-time.} }

@inproceedings{LV-concur08, address = {Toronto, Canada}, month = aug, year = 2008, volume = 5201, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {van Breugel, Franck and Chechik, Marsha}, acronym = {{CONCUR}'08}, booktitle = {{P}roceedings of the 19th {I}nternational {C}onference on {C}oncurrency {T}heory ({CONCUR}'08)}, author = {Lozes, {\'E}tienne and Villard, Jules}, title = {A Spatial Equational Logic for the Applied {{\(\pi\)}}-Calculus}, pages = {387-401}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/LV-concur08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/LV-concur08.pdf}, doi = {10.1007/978-3-540-85361-9_31}, abstract = {Spatial logics have been proposed to reason locally and modularly on algebraic models of distributed systems. In this paper we define the spatial equational logic A\(\pi\)L whose models are processes of the applied \(\pi\)-calculus. This extension of the \(\pi\)-calculus allows term manipulation and records communications as active substitutions in a frame, thus augmenting the underlying predefined equational theory. Our logic allows one to reason locally either on frames or on processes, thanks to static and dynamic spatial operators. We study the logical equivalences induced by various relevant fragments of~A\(\pi\)L, and~show in particular that the whole logic induces a coarser equivalence than structural congruence. We give characteristic formulae for some of these equivalences and for static equivalence. Going further into the exploration of A\(\pi\)L's expressivity, we~also show that it can eliminate standard term quantification.} }

@inproceedings{FS-mfcs08, address = {Toru{\'n}, Poland}, month = aug, year = 2008, volume = {5162}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Ochma{\'n}ski, Edward and Tyszkiewicz, Jerzy}, acronym = {{MFCS}'08}, booktitle = {{P}roceedings of the 33rd {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'08)}, author = {Finkel, Alain and Sangnier, Arnaud}, title = {Reversal-bounded Counter Machines Revisited}, pages = {323-334}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FS-mfcs08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FS-mfcs08.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/FS-mfcs08.ps}, doi = {10.1007/978-3-540-85238-4_26}, abstract = {We~extend the class of reversal-bounded counter machines by authorizing a finite number of alternations between increasing and decreasing mode over a given bound. We~prove that extended reversal-bounded counter machines also have effective semi-linear reachability sets. We~also prove that the property of being reversal-bounded is undecidable in general even when we fix the bound, whereas this problem becomes decidable when considering Vector Addition System with States.} }

@inproceedings{BDL-csl08, address = {Bertinoro, Italy}, month = sep, year = 2008, volume = 5213, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Kaminski, Michael and Martini, Simone}, acronym = {{CSL}'08}, booktitle = {{P}roceedings of the 17th {A}nnual {EACSL} {C}onference on {C}omputer {S}cience {L}ogic ({CSL}'08)}, author = {Brochenin, R{\'e}mi and Demri, St{\'e}phane and Lozes, {\'E}tienne}, title = {On~the Almighty Wand}, pages = {323-338}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BDL-csl08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BDL-csl08.pdf}, doi = {10.1007/978-3-540-87531-4_24}, abstract = {We investigate decidability, complexity and expressive power issues for (first-order) separation logic with one record field (herein called~SL) and its fragments. SL~can specify properties about the memory heap of programs with singly-linked lists. Separation logic with two record fields is known to be undecidable by reduction of finite satisfiability for classical predicate logic with one binary relation. Surprisingly, we~show that second-order logic is as expressive as SL and as a by-product we get undecidability of~SL. This is refined by showing that SL without the separating conjunction is as expressive as~SL, whence undecidable too. As~a consequence of this deep result, in~SL the magic wand can simulate the separating conjunction. By~contrast, we~establish that SL without the magic wand is decidable with non-elementary complexity by reduction from satisfiability for the first-order theory over finite words. Equivalence between second-order logic and separation logic extends to the case with more than one selector.} }

@inproceedings{bhhtv08ciaa, address = {San Francisco, California, USA}, month = jul, year = 2008, volume = 5148, series = {Lecture Notes in Computer Science}, publisher = {Springer-Verlag}, editor = {Ibarra, Oscar H. and Ravikumar, Bala}, acronym = {{CIAA}'08}, booktitle = {{P}roceedings of the 13th {I}nternational {C}onference on {I}mplementation and {A}pplication of {A}utomata ({CIAA}'08)}, author = {Bouajjani, Ahmed and Habermehl, Peter and Hol\'{\i}k, Luk{\'a}{\v{s}} and Touili, Tayssir and Vojnar, Tom{\'a}{\v{s}}}, title = {Antichain-based Universality and Inclusion Testing over Nondeterministic Finite Tree Automata}, pages = {57-67}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/bhhtv-ciaa08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/bhhtv-ciaa08.pdf}, doi = {10.1007/978-3-540-70844-5_7}, abstract = {We propose new antichain-based algorithms for checking universality and inclusion of nondeterministic tree automata. We have implemented these algorithms in a prototype tool and we present experiments which show that the algorithms provide a significant improvement over the traditional determinisation-based approaches. Furthermore, we use the proposed antichain-based inclusion checking algorithm to build an abstract regular tree model checking framework based entirely on nondeterministic tree automata. We show the significantly improved efficiency of this framework on a series of experiments with verifying various programs over dynamic tree-shaped data structures linked by pointers.} }

@techreport{LSV:08:10, author = {Villard, Jules and Lozes, {\'E}tienne and Treinen, Ralf}, title = {A Spatial Equational Logic for the Applied pi-calculus}, institution = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, year = 2008, month = mar, type = {Research Report}, number = {LSV-08-10}, url = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2008-10.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2008-10.pdf}, note = {44~pages}, abstract = {Spatial logics have been proposed to reason locally and modularly on algebraic models of distributed systems. In~this paper we~investigate a spatial equational logic (A\(\pi\)L) whose models are processes of the applied \(\pi\)-calculus, an extension of the \(\pi\)-calculus allowing term manipulation modulo a predefined equational theory, and wherein communications are recorded as active substitutions in a frame. Our logic allows us to reason locally either on frames or on processes, thanks to static and dynamic spatial operators. We study the logical equivalences induced by various relevant fragments of~A\(\pi\)L, and show in particular that the whole logic induces a coarser equivalence than structural congruence. We give characteristic formulae for this new equivalence as well as for static equivalence on frames. Going further into the exploration of A\(\pi\)L's expressivity, we also show that it can eliminate standard term quantication, and that the model-checking problem for the adjunct-free fragment of A\(\pi\)L can be reduced to satisfiability of a purely first-order logic of a term algebra.} }

@techreport{LSV:08:08, author = {Finkel, Alain and Leroux, J{\'e}r{\^o}me}, title = {Presburger Functions are Piecewise Linear}, institution = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, year = 2008, month = mar, type = {Research Report}, number = {LSV-08-08}, url = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2008-08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2008-08.pdf}, note = {9~pages}, abstract = {In this paper we geometrically characterize sets and functions definable in the first order additive theory of the reals and the integers, a decidable extension of the Presburger arithmetic combining both integral and real variables. We introduce the notion of polinear sets, an extension of the linear sets that characterizes these sets and we prove that a function is definable in this logic if and only if it is piecewise rational linear.} }

@inproceedings{CS-lics08, address = {Pittsburgh, Pennsylvania, USA}, month = jun, year = 2008, publisher = {{IEEE} Computer Society Press}, acronym = {{LICS}'08}, booktitle = {{P}roceedings of the 23rd {A}nnual {IEEE} {S}ymposium on {L}ogic in {C}omputer {S}cience ({LICS}'08)}, author = {Chambart, Pierre and Schnoebelen, {\relax Ph}ilippe}, title = {The Ordinal Recursive Complexity of Lossy Channel Systems}, pages = {205-216}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CS-lics08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CS-lics08.pdf}, doi = {10.1109/LICS.2008.47}, abstract = {We show that reachability and termination for lossy channel systems is exactly at level \(\mathcal{F}_{\omega^{\omega}}\) in the Fast-Growing Hierarchy of recursive functions, the first level that dominates all multiply-recursive functions.} }

@inproceedings{BFL-time08, address = {Montr{\'e}al, Canada}, month = jun, year = 2008, publisher = {{IEEE} Computer Society Press}, noeditor = {Demri, St{\'e}phane and Jensen, {\relax Ch}ristian S.}, acronym = {{TIME}'08}, booktitle = {{P}roceedings of the 15th {I}nternational {S}ymposium on {T}emporal {R}epresentation and {R}easoning ({TIME}'08)}, author = {Bouchy, Florent and Finkel, Alain and Leroux, J{\'e}r{\^o}me}, title = {Decomposition of Decidable First-Order Logics over Integers and Reals}, pages = {147-155}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFL-time08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFL-time08.pdf}, doi = {10.1109/TIME.2008.22}, abstract = {We tackle the issue of representing infinite sets of realvalued vectors. This paper introduces an operator for combining integer and real sets. Using this operator, we~decompose three well-known logics extending Presburger with reals. Our decomposition splits the logic into two parts: one~integer, and one decimal (\textit{i.e.},~on the interval~\([0,1[\)). We~also give some basis for an implementation of our representation.} }

@article{BFLP-sttt08, publisher = {Springer}, journal = {International Journal on Software Tools for Technology Transfer}, author = {Bardin, S{\'e}bastien and Finkel, Alain and Leroux, J{\'e}r{\^o}me and Petrucci, Laure}, title = {{FAST}: Acceleration from theory to practice}, year = 2008, month = oct, volume = 10, number = 5, pages = {401-424}, url = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2007-16.pdf}, doi = {10.1007/s10009-008-0064-3}, abstract = {Fast acceleration of symbolic transition systems~(\textsc{Fast}) is a tool for the analysis of systems manipulating unbounded integer variables. We~check safety properties by computing the reachability set of the system under study. Even if this reachability set is not necessarily recursive, we~use innovative techniques, namely symbolic representation, acceleration and circuit selection, to~increase convergence. \textsc{Fast} has proved to perform very well on case studies. This~paper describes the tool, from the underlying theory to the architecture choices. Finally, \textsc{Fast} capabilities are compared with those of other tools. A~range of case studies from the literature is investigated.} }

@misc{NB-SuMo-2006, author = {Bertrand, Nathalie}, title = {SuMo~-- Reachability analysis for lossy channels}, month = feb, year = {2006}, note = {See~\cite{BBS-forte06} for a description. Written in~OCaml (3000~lines)}, note-fr = {Voir la description dans~\cite{BBS-forte06}. {\'E}crit en~OCaml (3000~lignes)} }

@misc{averiles07-f1.6, author = {Ourghanlian, Alain and Bozga, Marius and Roglewicz, Adam and Sangnier, Arnaud}, title = {Projet {RNTL} {A}veriles~-- Fourniture F1.6~: Exp{\'e}rimentation}, year = 2007, month = sep, type = {Contract Report}, note = {16~pages}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f16.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f16.pdf} }

@misc{averiles07-f1.4, author = {LIAFA and LSV and Verimag}, title = {Projet {RNTL} {A}veriles~-- Fourniture F1.4~: Prototypes d'outil}, year = 2007, month = sep, type = {Contract Report}, note = {3~pages}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f14.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f14.pdf} }

@misc{averiles07-f1.3, author = {LIAFA and {CRIL Technology} and {EDF R\&D} and LSV and Verimag}, title = {Projet {RNTL} {A}veriles~-- Fourniture F1.3~: Algorithmes de v{\'e}rification}, year = 2007, month = sep, type = {Contract Report}, note = {19~pages}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f13.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f13.pdf} }

@misc{averiles07-f1.2, author = {LIAFA and {CRIL Technology} and {EDF R\&D} and LSV and Verimag}, title = {Projet {RNTL} {A}veriles~-- Fourniture F1.2~: Extraction de mod{\`e}les}, year = 2007, month = sep, type = {Contract Report}, note = {19~pages}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f12.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f12.pdf} }

@misc{averiles07-f1.1, author = {LIAFA and {CRIL Technology} and {EDF R\&D} and LSV and Verimag}, title = {Projet {RNTL} {A}veriles~-- Fourniture F1.1~: Mod{\`e}les}, year = 2007, month = sep, type = {Contract Report}, note = {6~pages}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f11.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-f11.pdf} }

@misc{averiles07, author = {LIAFA and {CRIL Technology} and {EDF R\&D} and LSV and Verimag}, title = {Rapport {\`a} mi-parcours du projet {RNTL} {A}veriles (analyse et v{\'e}rification de logiciels embarqu{\'e}s avec structures de m{\'e}moire dynamique}, year = 2007, month = sep, type = {Contract Report}, note = {4~pages}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-MP.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/averiles-MP.pdf} }

@inproceedings{VLC-tacas10, address = {Paphos, Cyprus}, month = mar, year = 2010, volume = {6015}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Esparza, Javier and Majumdar, Rupak}, acronym = {{TACAS}'10}, booktitle = {{P}roceedings of the 16th {I}nternational {C}onference on {T}ools and {A}lgorithms for {C}onstruction and {A}nalysis of {S}ystems ({TACAS}'10)}, author = {Villard, Jules and Lozes, {\'E}tienne and Calcagno, Cristiano}, title = {Tracking Heaps that Hop with Heap-Hop}, pages = {275-279}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/VLC-tacas10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/VLC-tacas10.pdf}, doi = {10.1007/978-3-642-12002-2_23}, abstract = {Heap-Hop is a program prover for concurrent heap-manipulating programs that use Hoare monitors and message-passing synchronization. Programs are annotated with pre and post-conditions and loop invariants, written in a fragment of separation logic. Communications are governed by a form of session types called contracts. Heap-Hop can prove safety and race-freedom and, thanks to contracts, absence of memory leaks and deadlock-freedom. It has been used in several case studies, including concurrent programs for copyless list transfer, service provider protocols, and load-balancing parallel tree disposal.} }

@inproceedings{DS-fossacs10, address = {Paphos, Cyprus}, month = mar, year = 2010, volume = {6014}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Ong, C.-H. Luke}, acronym = {{FoSSaCS}'10}, booktitle = {{P}roceedings of the 13th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'10)}, author = {Demri, St{\'e}phane and Sangnier, Arnaud}, title = {When Model-Checking Freeze {LTL} over Counter Machines Becomes Decidable}, pages = {176-190}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DS-fossacs10.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DS-fossacs10.pdf}, doi = {10.1007/978-3-642-12032-9_13}, abstract = {We study the decidability status of model-checking freeze LTL over various subclasses of counter machines for which the reachability problem is known to be decidable (reversal-bounded counter machines, vector additions systems with states, flat counter machines, one-counter machines). In freeze LTL, a register can store a counter value and at some future position an equality test can be done between a register and a counter value. Herein, we complete an earlier work started on one-counter machines by considering other subclasses of counter machines, and especially the class of reversal-bounded counter machines. This gives us the opportuniy to provide a systematic classification that distinguishes determinism vs. nondeterminism and we consider subclasses of formulae by restricting the set of atomic formulae or\slash and the polarity of the occurrences of the freeze operators, leading to the flat fragment.} }

@inproceedings{CS-fossacs10, address = {Paphos, Cyprus}, month = mar, year = 2010, volume = {6014}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Ong, C.-H. Luke}, acronym = {{FoSSaCS}'10}, booktitle = {{P}roceedings of the 13th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'10)}, author = {Chambart, Pierre and Schnoebelen, {\relax Ph}ilippe}, title = {Toward a compositional theory of leftist grammars and transformations}, pages = {237-251}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CS-fossacs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CS-fossacs10.pdf}, doi = {10.1007/978-3-642-12032-9_17}, abstract = {Leftist grammars [Motwani \textit{et~al.}, STOC~2000] are special semi-Thue systems where symbols can only insert or erase to their left. We~develop a theory of leftist grammars seen as word transformers as a tool toward rigorous analyses of their computational power. Our~main contributions in this first paper are (1)~constructions proving that leftist transformations are closed under compositions and transitive closures, and (2)~a~proof that bounded reachability is NP-complete even for leftist grammars with acyclic rules.} }

@article{schmitz-scp10, publisher = {Elsevier Science Publishers}, journal = {Science of Computer Programming}, author = {Sylvain Schmitz}, title = {An Experimental Ambiguity Detection Tool}, volume = 75, number = {1-2}, pages = {71-84}, month = jan, year = 2010, doi = {10.1016/j.scico.2009.07.002}, url = {http://hal.archives-ouvertes.fr/hal-00436398}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/schmitz-scp10.pdf}, abstract = {Although programs convey an unambiguous meaning, the grammars used in practice to describe their syntax are often ambiguous, and completed with disambiguation rules. Whether these rules achieve the removal of all the ambiguities while preserving the original intended language can be difficult to ensure. We present an experimental ambiguity detection tool for GNU Bison, and illustrate how it can assist a grammatical development for a subset of Standard~ML.} }

@inproceedings{CLPV-vmcai10, address = {Madrid, Spain}, month = jan, year = 2010, volume = 5944, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Barthe, Gilles and Hermenegildo, Manuel}, acronym = {{VMCAI}'10}, booktitle = {{P}roceedings of the 11th {I}nternational {C}onference on {V}erification, {M}odel {C}hecking and {A}bstract {I}nterpretation ({VMCAI}'10)}, author = {Chadha, Rohit and Legay, Axel and Prabhakar, Pavithra and Viswanathan, Mahesh}, title = {Complexity bounds for the verification of real-time software}, pages = {95-111}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CLPV-vmcai10.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CLPV-vmcai10.pdf}, doi = {10.1007/978-3-642-11319-2_10}, abstract = {We present uniform approaches to establish complexity bounds for decision problems such as reachability and simulation, that arise naturally in the verification of timed software systems. We model timed software systems as timed automata augmented with a data store (like a pushdown stack) and show that there is at least an exponential blowup in complexity of verification when compared with untimed systems. Our proof techniques also establish complexity results for boolean programs, which are automata with stores that have additional boolean variables.} }

@phdthesis{bouchy-phd2009, author = {Bouchy, Florent}, title = {Logiques et mod{\`e}les pour la v{\'e}rification de syst{\`e}mes infinis}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, type = {Th{\`e}se de doctorat}, year = 2009, month = nov, url = {http://www.lsv.fr/Publis/PAPERS/PDF/FB-these09.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/FB-these09.pdf} }

@mastersthesis{dimino-m1, author = {Dimino, J{\'e}r{\'e}mie}, title = {Les syst{\`e}mes {\`a} canaux non-fiables vus comme des transducteurs}, school = {{M}aster {P}arisien de {R}echerche en {I}nformatique, Paris, France}, type = {Rapport de stage de {M1}}, year = {2009}, month = oct, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/dimino-m1.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/dimino-m1.pdf} }

@inproceedings{FS-sofsem10, address = {\v{S}pindler\r{u}v Ml\'{y}n, Czech Republic}, month = jan, year = 2010, volume = 5901, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Peleg, David and Muscholl, Anca}, acronym = {{SOFSEM}'10}, booktitle = {{P}roceedings of the 36th International Conference on Current Trends in Theory and Practice of Computer Science ({SOFSEM}'10)}, author = {Finkel, Alain and Sangnier, Arnaud}, title = {Mixing coverability and reachability to analyze {VASS} with one zero-test}, pages = {394-406}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FS-sofsem10.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FS-sofsem10.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/FS-sofsem10.ps}, doi = {10.1007/978-3-642-11266-9_33}, abstract = {We study Vector Addition Systems with States (VASS) extended in such a way that one of the manipulated integer variables can be tested to zero. For this class of system, it has been proved that the reachability problem is decidable. We prove here that boundedness, termination and reversal-boundedness are decidable for VASS with one zero-test. To decide reversal-boundedness, we provide an original method which mixes both the construction of the coverability graph for VASS and the computation of the reachability set of reversal-bounded counter machines. The same construction can be slightly adapted to decide boundedness and hence termination.} }

@inproceedings{DJLL-fsttcs09, address = {Kanpur, India}, month = dec, year = 2009, volume = 4, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Kannan, Ravi and Narayan Kumar, K.}, acronym = {{FSTTCS}'09}, booktitle = {{P}roceedings of the 29th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'09)}, author = {Demri, St{\'e}phane and Jurdzi{\'n}ski, Marcin and Lachish, Oded and Lazi{\'c}, Ranko}, title = {The covering and boundedness problems for branching vector addition systems}, pages = {181-192}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/djll-fsttcs09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/djll-fsttcs09.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2009.2317}, abstract = {The covering and boundedness problems for branching vector addition systems are shown complete for doubly-exponential time.} }

@inproceedings{VLC-aplas09, address = {Seoul, Korea}, month = dec, year = 2009, volume = {5904}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Hu, Zhenjiang}, acronym = {{APLAS}'09}, booktitle = {{P}roceedings of the 7th {A}sian {S}ymposium on {P}rogramming {L}anguages and {S}ystems ({APLAS}'09)}, author = {Villard, Jules and Lozes, {\'E}tienne and Calcagno, Cristiano}, title = {Proving Copyless Message Passing}, pages = {194-209}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/VLC-aplas09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/VLC-aplas09.pdf}, doi = {10.1007/978-3-642-10672-9_15}, abstract = {Handling concurrency using a shared memory and locks is tedious and error-prone. One solution is to use message passing instead. We study here a particular, contract-based flavor that makes the ownership transfer of messages explicit. In this case, ownership of the heap region representing the content of a message is lost upon sending, which can lead to efficient implementations. In this paper, we define a proof system for a concurrent imperative programming language implementing this idea and inspired by the Singularity OS. The proof system, for which we prove soundness, is an extension of separation logic, which has already been used successfully to study various ownership-oriented paradigms.} }

@inproceedings{BFSP-infinity09, address = {Bologna, Italy}, month = nov, year = 2009, volume = 10, series = {Electronic Proceedings in Theoretical Computer Science}, editor = {Farzan, Azadeh and Legay, Axel}, acronym = {{INFINITY}'09}, booktitle = {{P}roceedings of the 11th {I}nternational {W}orkshops on {V}erification of {I}nfinite {S}tate {S}ystems ({INFINITY}'09)}, author = {Bouchy, Florent and Finkel, Alain and San{ }Pietro, Pierluigi}, title = {Dense-choice Counter Machines Revisited}, pages = {3-22}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFSP-infinity09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFSP-infinity09.pdf}, doi = {10.4204/EPTCS.10.1}, abstract = {This paper clarifies the picture about Dense-choice Counter Machines, which have been less studied than (discrete) Counter Machines. We revisit the definition of {"}Dense Counter Machines{"} so that it now extends (discrete) Counter Machines, and we provide new undecidability and decidability results. Using the first-order additive mixed theory of reals and integers, we give a logical characterization of the sets of configurations reachable by reversal-bounded Dense-choice Counter Machines.} }

@inproceedings{BHK-rp09, address = {Palaiseau, France}, month = sep, year = 2009, volume = 5797, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Bournez, Olivier and Potapov, Igor}, acronym = {{RP}'09}, booktitle = {{P}roceedings of the 3rd {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'09)}, author = {Boichut, Yohan and H{\'e}am, Pierre-Cyrille and Kouchnarenko, Olga}, title = {How to Tackle Integer Weighted Automata Positivity}, pages = {79-92}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BHK-rp09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BHK-rp09.pdf}, doi = {10.1007/978-3-642-04420-5_9}, abstract = {This paper is dedicated to candidate abstractions to capture relevant aspects of the integer weighted automata. The expected effect of applying these abstractions is studied to build the deterministic reachability graphs allowing us to semi-decide the positivity problem on these automata. Moreover, the papers reports on the implementations and experimental results, and discusses other encodings.} }

@article{BCHK-ijfcs09, publisher = {World Scientific}, journal = {International Journal of Foundations of Computer Science}, author = {Boichut, Yohan and Courbis, Rom{\'e}o and H{\'e}am, Pierre-Cyrille and Kouchnarenko, Olga}, title = {Handling Non-left Linear Rules when Completing Tree Automata}, volume = 20, number = 5, pages = {837-849}, year = 2009, month = oct, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BCHK-ijfcs09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BCHK-ijfcs09.pdf}, doi = {10.1142/S0129054109006917}, abstract = {This paper addresses the following general problem of tree regular model-checking: decide whether \(\mathcal{R}^*(\mathcal{L}) \cap \mathcal{L}_p = \emptyset\) where \(\mathcal{R}^*\) is the reflexive and transitive closure of a successor relation induced by a term rewriting system~\(\mathcal{R}\), and \(\mathcal{L}\) and~\(\mathcal{L}_p\) are both regular tree languages. We~develop an automatic approximation-based technique to handle this---undecidable in general---problem in the case when term rewriting system rules are non left-linear.} }

@article{BDL-apal09, publisher = {Elsevier Science Publishers}, journal = {Annals of Pure and Applied Logics}, author = {Brochenin, R{\'e}mi and Demri, St{\'e}phane and Lozes, {\'E}tienne}, title = {Reasoning about sequences of memory states}, volume = {161}, number = {3}, pages = {305-323}, year = 2009, month = dec, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BDL-apal09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BDL-apal09.pdf}, doi = {10.1016/j.apal.2009.07.004}, abstract = {Motivated by the verification of programs with pointer variables, we introduce a temporal logic LTL\textsuperscript{mem} whose underlying assertion language is the quantifier-free fragment of separation logic and the temporal logic on the top of it is the standard linear-time temporal logic LTL. We analyze the complexity of various model-checking and satisfiability problems for LTL\textsuperscript{mem}, considering various fragments of separation logic (including pointer arithmetic), various classes of models (with or without constant heap), and the influence of fixing the initial memory state. We provide a complete picture based on these criteria. Our main decidability result is pspace-completeness of the satisfiability problems on the record fragment and on a classical fragment allowing pointer arithmetic. \(\Sigma_1^0\)-completeness or \(\Sigma_1^1\)-completeness results are established for various problems by reducing standard problems for Minsky machines, and underline the tightness of our decidability results.} }

@article{DG-jlc09, publisher = {Oxford University Press}, journal = {Journal of Logic and Computation}, author = {Demri, St{\'e}phane and Gascon, R{\'e}gis}, title = {The Effects of Bounding Syntactic Resources on {P}resburger {LTL}}, pages = {1541-1575}, volume = {19}, number = {6}, month = dec, year = 2009, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DG-jlc09.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DG-jlc09.pdf}, doi = {10.1093/logcom/exp037}, abstract = {LTL over Presburger constraints is the extension of LTL where the atomic formulae are quantifier-free Presburger formulae having as free variables the counters at different states of the model. This logic is known to admit undecidable satisfiability and model-checking problems. We~study decidability and complexity issues for fragments of LTL with Presburger constraints obtained by restricting the syntactic resources of the formulae (the number of variables, the maximal distance between two states for which counters can be compared and, to a smaller extent, the set of Presburger constraints) while preserving the strength of the logical operators. We~provide a complete picture refining known results from the literature. We~show that model-checking and satisfiability problems for the fragments of LTL with difference constraints restricted to two variables and distance one and to one variable and distance two are highly undecidable, enlarging significantly the class of known undecidable fragments. On the positive side, we prove that the fragment restricted to one variable and to distance one augmented with propositional variables is \textsc{pspace}-complete. Since the atomic formulae can state quantitative properties on the counters, this extends some results about model-checking pushdown systems and one-counter automata. In~order to establish the pspace upper bound, we show that the nonemptiness problem for B{\"u}chi one-counter automata taking values in~\(\mathbb{Z}\) and allowing zero tests and sign tests, is~only \textsc{nlogspace}-complete. Finally, we~establish that model-checking one-counter automata with complete quantifier-free Presburger LTL restricted to one variable is also \textsc{pspace}-complete whereas the satisfiability problem is undecidable.} }

@inproceedings{DHL-mbt09, address = {York, UK}, month = oct, year = 2009, number = {2}, volume = {253}, series = {Electronic Notes in Theoretical Computer Science}, publisher = {Elsevier Science Publishers}, acronym = {{MBT}'09}, booktitle = {{P}roceedings of the 5th Workshop on Model-Based Testing ({MBT}'09)}, author = {Dadeau, Fr{\'e}d{\'e}ric and H{\'e}am, Pierre-Cyrille and Levrey, Jocelyn}, title = {On the Use of Uniform Random Generation of Automata for Testing}, pages = {37-51}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DHL-mbt09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DHL-mbt09.pdf}, doi = {10.1016/j.entcs.2009.09.050 }, abstract = {Developing efficient and automatic testing techniques is one of the major challenges facing software validation community. In this paper, we show how a uniform random generation process of finite automata, developed in a recent work by Bassino and Nicaud, is relevant for many faces of automatic testing. The main contribution is to show how to combine two major testing approaches: model-based testing and random testing. This leads to a new testing technique successfully experimented on a realistic case study. We also illustrate how the power of random testing, applied on a Chinese Postman Problem implementation, points out an error in a well-known algorithm. Finally, we provide some statistics on model-based testing algorithms.} }

@article{BHK-njc09, journal = {Nordic Journal of Computing}, author = {Boichut, Yohan and H{\'e}am, Pierre-Cyrille and Kouchnarenko, Olga}, title = {Approximation-based Tree Regular Model-Checking}, volume = {14}, number = {3}, pages = {216-241}, month = oct, year = 2008, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BHK-njc09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BHK-njc09.pdf}, abstract = {This paper addresses the following general problem of tree regular model-checking: decide whether \(\mathcal{R}^*(L)\cap L_{p} = \varnothing\) where \(\mathcal{R}^*\) is the reflexive and transitive closure of a successor relation induced by a term rewriting system~\(\mathcal{R}\), and \(L\) and \(L_p\) are both regular tree languages. We develop an automatic approximation-based technique to handle this---undecidable in general---problem in most practical cases, extending a recent work by Feuillade, Genet and Viet~Triem~Tong. We also make this approach fully automatic for practical validation of security protocols.} }

@inproceedings{CHK-ciaa09, address = {Sydney, Australia}, month = jul, year = 2009, volume = 5642, series = {Lecture Notes in Computer Science}, publisher = {Springer-Verlag}, editor = {Maneth, Sebastian}, acronym = {{CIAA}'09}, booktitle = {{P}roceedings of the 14th {I}nternational {C}onference on {I}mplementation and {A}pplication of {A}utomata ({CIAA}'09)}, author = {Courbis, Rom{\'e}o and H{\'e}am, Pierre-Cyrille and Kouchnarenko, Olga}, title = {{TAGED} Approximations for Veriying Temporal Patterns}, pages = {135-144}, doi = {10.1007/978-3-642-02979-0_17}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CHK-ciaa09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/CHK-ciaa09.pdf}, abstract = {This paper investigates the use of tree automata with global equalities and disequalities (TAGED for short) in reachability analysis over term rewriting systems (TRSs). The reachability problem being in general undecidable on non terminating TRSs, we provide TAGED-based construction, and then design approximation-based semi-decision procedures to model-check useful temporal patterns on infinite state rewriting graphs. To show that the above TAGED-based construction can be effectively carried out, complexity analysis for rewriting TAGED-definable languages is given.} }

@inproceedings{HNS-ciaa09, address = {Sydney, Australia}, month = jul, year = 2009, volume = 5642, series = {Lecture Notes in Computer Science}, publisher = {Springer-Verlag}, editor = {Maneth, Sebastian}, acronym = {{CIAA}'09}, booktitle = {{P}roceedings of the 14th {I}nternational {C}onference on {I}mplementation and {A}pplication of {A}utomata ({CIAA}'09)}, author = {H{\'e}am, Pierre-Cyrille and Nicaud, Cyril and Schmitz, Sylvain}, title = {Random Generation of Deterministic Tree (Walking) Automata}, pages = {115-124}, doi = {10.1007/978-3-642-02979-0_15}, url = {http://hal.inria.fr/inria-00408316}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HNS-ciaa09.pdf}, abstract = {Uniform random generators deliver a simple empirical means to estimate the average complexity of an algorithm. We present a general rejection algorithm that generates sequential letter-to-letter transducers up to isomorphism. We tailor this general scheme to randomly generate deterministic tree walking automata and deterministic top-down tree automata. We apply our implementation of the generator to the estimation of the average complexity of a deterministic tree walking automata to nondeterministic top-down tree automata construction we also implemented.} }

@inproceedings{FGL-icalp09, address = {Rhodes, Greece}, month = jul, year = 2009, volume = 5556, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Albers, Susanne and Marchetti-Spaccamela, Alberto and Matias, Yossi and Thomas, Wolfgang}, acronym = {{ICALP}'09}, booktitle = {{P}roceedings of the 36th {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'09)}, author = {Finkel, Alain and Goubault{-}Larrecq, Jean}, title = {Forward Analysis for {WSTS}, Part~{II}: Complete {WSTS}}, pages = {188-199}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FGL-icalp09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FGL-icalp09.pdf}, doi = {10.1007/978-3-642-02930-1_16}, abstract = {We~describe a simple, conceptual forward analysis procedure for \(\infty\)-complete WSTS~\(\mathcal{S}\). This computes the \emph{clover} of a state~\(s_0\) , \textit{i.e.}, a~finite description of the closure of the cover of~\(s_0\) . When \(S\) is the completion of a WSTS~\(\mathcal{X}\), the clover in~\(\mathcal{S}\) is a finite description of the cover in~\(\mathcal{X}\). We~show that this applies exactly when \(\mathcal{X}\) is an \(\omega^2\)-WSTS, a~new robust class of WSTS. We~show that our procedure terminates in more cases than the generalized Karp-Miller procedure on extensions of Petri nets. We characterize the WSTS where our procedure terminates as those that are \emph{clover-flattable}. Finally, we~apply this to well-structured counter systems.} }

@inproceedings{BBL-Fossacs09, address = {York, UK}, month = mar, year = 2009, volume = 5504, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {de Alfaro, Luca}, acronym = {{FoSSaCS}'09}, booktitle = {{P}roceedings of the 12th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'09)}, author = {Bansal, Kshitij and Brochenin, R{\'e}mi and Lozes, {\'E}tienne}, title = {Beyond Shapes: Lists with Ordered Data}, pages = {425-439}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BBL-fossacs09.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BBL-fossacs09.pdf}, doi = {10.1007/978-3-642-00596-1_30}, abstract = {Standard analysis on recursive data structures restrict their attention to shape properties (for instance, a program that manipulates a list returns a list), excluding properties that deal with the actual content of these structures. For instance, these analysis would not establish that the result of merging two ordered lists is an ordered list. Separation logic, one of the prominent framework for these kind of analysis, proposed a heap model that could represent data, but, to our knowledge, no predicate dealing with data has ever been integrated to the logic while preserving decidability. We~establish decidability for (first-order) separation logic with a predicate that allows to compare two successive data in a list. We~then consider the extension where two data in arbitrary positions may be compared, and establish the undecidability in general. We~define a guarded fragment that turns out to be both decidable and sufficiently expressive to prove the preservation of the loop invariant of a standard program merging ordered lists. We~finally consider the extension with the magic-wand and prove that, by constrast with the data-free case, even a very restricted use of the magic wand already introduces undecidability.} }

@article{LHS-lmcs08, journal = {Logical Methods in Computer Science}, author = {Lozes, {\'E}tienne and Hirschkoff, Daniel and Sangiorgi, Davide}, title = {Separability in the Ambient Logic}, volume = 4, number = {3:4}, year = 2008, month = sep, nopages = {}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/LHS-lmcs08.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/LHS-lmcs08.pdf}, ps = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PS/LHS-lmcs08.ps}, doi = {10.2168/LMCS-4(3:4)2008}, abstract = {The Ambient Logic~(AL) has been proposed for expressing properties of process mobility in the calculus of Mobile Ambients~(MA), and as a basis for query languages on semistructured data. \par We study some basic questions concerning the discriminating power of~AL, focusing on the equivalence on processes induced by the logic~(\(=_{L}\)). As underlying calculi besides~MA we~consider a subcalculus in which an image-finiteness condition holds and that we prove to be Turing complete. Synchronous variants of these calculi are studied as well. \par In these calculi, we provide two operational characterisations of~\(=_{L}\): a~coinductive one (as a form of bisimilarity) and an inductive one (based on structual properties of processes). After showing \(=_{L}\) to be stricly finer than barbed congruence, we establish axiomatisations of~\(=_{L}\) on the subcalculus of~MA (both the asynchronous and the synchronous version), enabling us to relate~\(=_{L}\) to structural congruence. We~also present some (un)decidability results that are related to the above separation properties for~AL: the~undecidability of~\(=_{L}\) on~MA and its decidability on the subcalculus.} }

@inproceedings{FGL-stacs2009, address = {Freiburg, Germany}, month = feb, year = 2009, volume = 3, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Albers, Susanne and Marion, Jean-Yves}, acronym = {{STACS}'09}, booktitle = {{P}roceedings of the 26th {A}nnual {S}ymposium on {T}heoretical {A}spects of {C}omputer {S}cience ({STACS}'09)}, author = {Finkel, Alain and Goubault{-}Larrecq, Jean}, title = {Forward Analysis for~{WSTS}, Part~{I}: Completions}, pages = {433-444}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FGL-stacs2009.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/FGL-stacs2009.pdf}, abstract = {Well-structured transition systems provide the right foundation to compute a finite basis of the set of predecessors of the upward closure of a state. The~dual problem, to compute a finite representation of the set of successors of the downward closure of a state, is~harder: Until now, the theoretical framework for manipulating downward-closed sets was missing. We~answer this problem, using insights from domain theory (dcpos and ideal completions), from topology (sobrifications), and shed new light on the notion of adequate domains of limits.} }

@techreport{rr-lsv-10-23, author = {Bonnet, R{\'e}mi and Finkel, Alain and Haddad, Serge and Rosa{-}Velardo, Fernando}, title = {Comparing Petri Data Nets and Timed Petri Nets}, institution = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, year = {2010}, month = dec, type = {Research Report}, number = {LSV-10-23}, url = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2010-23.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2010-23.pdf}, note = {16~pages}, abstract = {Well-Structured Transitions Systems (WSTS) constitute a generic class of infinite-state systems for which several properties like coverability remain decidable. The family of coverability languages that they generate is an appropriate criterium for measuring their expressiveness. Here we establish that Petri Data nets (PDNs) and Timed Petri nets (TdPNs), two powerful classes of WSTS are equivalent w.r.t this criterium.} }

@mastersthesis{bonnet-master, author = {Bonnet, R{\'e}mi}, title = {Well-structured {P}etri-nets extensions with data}, school = {{M}aster Computer Science, EPFL, Lausanne, Switzerland}, type = {Rapport de {M}aster}, year = {2010}, month = mar, url = {http://www.lsv.fr/Publis/PAPERS/PDF/bonnet-m2.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/bonnet-m2.pdf} }

@incollection{DR-lgtcs10, month = jan, year = 2011, publisher = {Cambridge University Press}, booktitle = {Lectures in Game Theory for Computer Scientists}, editor = {Apt, Krzysztof R. and Gr{\"a}del, Erich}, author = {Doyen, Laurent and Raskin, Jean-Fran{\c{c}}ois}, title = {Games with Imperfect Information: Theory and Algorithms}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DR-lgtcs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DR-lgtcs10.pdf}, ps = {DR-lgtcs10.ps} }

@article{CDH-lmcs10, journal = {Logical Methods in Computer Science}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Henzinger, {\relax Th}omas A.}, title = {Expressiveness and Closure Properties for Quantitative Languages}, volume = 6, number = {3:10}, nopages = {}, month = sep, year = 2010, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDH-lmcs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDH-lmcs10.pdf}, ps = {CDH-lmcs10.ps}, doi = {10.2168/LMCS-6(3:10)2010}, abstract = {Weighted automata are nondeterministic automata with numerical weights on transitions. They can define quantitative languages~\(L\) that assign to each word~\(w\) a real number~\(L(w)\). In the case of infinite words, the value of a run is naturally computed as the maximum, limsup, liminf, limit-average, or discounted-sum of the transition weights. The value of a word \(w\) is the supremum of the values of the runs over \(w\). We study expressiveness and closure questions about these quantitative languages.\par We first show that the set of words with value greater than a threshold can be non-\(omega\)-regular for deterministic limit-average and discounted-sum automata, while this set is always \(omega\)-regular when the threshold is isolated (i.e., some neighborhood around the threshold contains no word). In the latter case, we prove that the \(omega\)-regular language is robust against small perturbations of the transition weights.\par We next consider automata with transition weights~\(0\) or \(1\) and show thatthey are as expressive as general weighted automata in the limit-average case, but not in the discounted-sum case.\par Third, for quantitative languages \(L_1\) and~\(L_2\), we consider the operations\(max(L_1,L_2)\), \(min(L_1,L_2)\), and \(1-L_1\), which generalize the booleanoperations on languages, as well as the sum \(L_1 + L_2\). We establish the closure properties of all classes of quantitative languages with respect to these four operations.} }

@inproceedings{CD-lpar10, address = {Yogyakarta, Indonesia}, month = oct, year = 2010, volume = {6397}, series = {Lecture Notes in Artificial Intelligence}, publisher = {Springer}, editor = {Fernm{\"u}ller, Chrisaitn G. and Voronkov, Andrei}, acronym = {{LPAR}'10}, booktitle = {{P}roceedings of the 17th {I}nternational {C}onference on {L}ogic for {P}rogramming, {A}rtificial {I}ntelligence, and {R}easoning ({LPAR}'10)}, author = {Chatterjee, Krishnendu and Doyen, Laurent}, title = {The Complexity of Partial-Observation Parity Games}, pages = {1-14}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-lpar10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-lpar10.pdf}, ps = {CD-lpar10.ps}, doi = {10.1007/978-3-642-16242-8_1}, abstract = {We consider two-player zero-sum games on graphs. On the basis of the information available to the players these games can be classified as follows: (a)~partial-observation (both players have partial view of the game); (b)~one-sided partial-observation (one player has partial-observation and the other player has complete-observation); and (c)~complete-observation (both players have complete view of the game). We survey the complexity results for the problem of deciding the winner in various classes of partial-observation games with \(\omega\)-regular winning conditions specified as parity objectives. We present a reduction from the class of parity objectives that depend on sequence of states of the game to the sub-class of parity objectives that only depend on the sequence of observations. We also establish that partial-observation acyclic games are PSPACE-complete.} }

@article{AHLNW-mscs10, publisher = {Cambridge University Press}, journal = {Mathematical Structures in Computer Science}, author = {Antonik, Adam and Huth, Michael and Larsen, Kim~G. and Nyman, Ulrik and W{\k{a}}sowski, Andrzej}, title = {Modal and mixed specifications: key decision problems and their complexities}, volume = 10, number = 1, month = feb, year = 2010, pages = {75-103}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/AHLNW-mscs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/AHLNW-mscs10.pdf}, doi = {10.1017/S0960129509990260}, abstract = {Modal and mixed transition systems are specification formalisms that allow the mixing of over- and under-approximation. We discuss three fundamental decision problems for such specifications: \begin{itemize} \item whether a set of specifications has a common implementation; \item whether an individual specification has an implementation; and \item whether all implementations of an individual specification are implementations of another one. \end{itemize} For each of these decision problems we investigate the worst-case computational complexity for the modal and mixed cases. We show that the first decision problem is EXPTIME-complete for both modal and mixed specifications. We prove that the second decision problem is EXPTIME-complete for mixed specifications (it is known to be trivial for modal ones). The third decision problem is also shown to be EXPTIME-complete for mixed specifications.} }

@inproceedings{CDHR-fsttcs10, address = {Chennai, India}, month = dec, year = 2010, volume = 8, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Lodaya, Kamal and Mahajan, Meena}, acronym = {{FSTTCS}'10}, booktitle = {{P}roceedings of the 30th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'10)}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Henzinger, {\relax Th}omas A. and Raskin, Jean-Fran{\c{c}}ois}, title = {Generalized Mean-payoff and Energy Games}, pages = {505-516}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDHR-fsttcs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDHR-fsttcs10.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2010.505} }

@inproceedings{BFLZ-fsttcs10, address = {Chennai, India}, month = dec, year = 2010, volume = 8, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Lodaya, Kamal and Mahajan, Meena}, acronym = {{FSTTCS}'10}, booktitle = {{P}roceedings of the 30th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'10)}, author = {Bonnet, R{\'e}mi and Finkel, Alain and Leroux, J{\'e}r{\^o}me and Zeitoun, Marc}, title = {Place-Boundedness for Vector Addition Systems with one zero-test}, pages = {192-203}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BFLZ-fsttcs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BFLZ-fsttcs10.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2010.192}, abstract = {Reachability and boundedness problems have been shown decidable for Vector Addition Systems with one zero-test. Surprisingly, place-boundedness remained open. We provide here a variation of the Karp-Miller algorithm to compute a basis of the downward closure of the reachability set which allows to decide place-boundedness. This forward algorithm is able to pass the zero-tests thanks to a finer cover, hybrid between the reachability and cover sets, reclaiming accuracy on one component. We show that this filtered cover is still recursive, but that equality of two such filtered covers, even for usual Vector Addition Systems (with no zero-test), is undecidable.} }

@article{LV-dc10, publisher = {Springer}, journal = {Distributed Computing}, author = {Lozes, {\'E}tienne and Villard, Jules}, title = {A~spatial equational logic for the applied \(\pi\)-calculus}, pages = {61-83}, volume = 23, number = 1, year = 2010, month = sep, url = {http://www.lsv.fr/Publis/PAPERS/PDF/LV-discomp10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LV-discomp10.pdf}, doi = {10.1007/s00446-010-0112-6}, abstract = {Spatial logics have been proposed to reason locally and modularly on algebraic models of distributed systems. In this paper we define the spatial equational logic \(\textsf{A}\pi\textsf{L}\) whose models are processes of the applied \(\pi\)-calculus. This extension of the \(\pi\)-calculus allows term manipulation and records communications as aliases in a frame, thus augmenting the predefined underlying equational theory. Our logic allows one to reason locally either on frames or on processes, thanks to static and dynamic spatial operators. We study the logical equivalences induced by various relevant fragments of \(\textsf{A}\pi\textsf{L}\), and show in particular that the whole logic induces a coarser equivalence than structural congruence. We give characteristic formulae for some of these equivalences and for static equivalence. Going further into the exploration of \(\textsf{A}\pi\textsf{L}\)'s expressivity, we also show that it can eliminate standard term quantification.} }

@inproceedings{phs-rp10, address = {Brno, Czech Republic}, month = aug, year = 2010, volume = 6227, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Ku{\v c}era, Anton{\'\i}n and Potapov, Igor}, acronym = {{RP}'10}, booktitle = {{P}roceedings of the 4th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'10)}, author = {Schnoebelen, {\relax Ph}ilippe}, title = {Lossy Counter Machines Decidability Cheat Sheet}, pages = {51-75}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/phs-rp10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/phs-rp10.pdf}, doi = {10.1007/978-3-642-15349-5_4}, abstract = {Lossy counter machines (LCM's) are a variant of Minsky counter machines based on weak (or~unreliable) counters in the sense that they can decrease nondeterministically and without notification. This model, introduced by R.~Mayr [TCS~297:337-354 (2003)], is not yet very well known, even though it has already proven useful for establishing hardness results.\par In this paper we survey the basic theory of LCM's and their verification problems, with a focus on the decidability/undecidability divide. } }

@inproceedings{DHLN-acsd10, address = {Braga, Portugal}, month = jun, year = 2010, publisher = {{IEEE} Computer Society Press}, editor = {Gomes, Lu{\'\i}s and Khomenko, Victor}, acronym = {{ACSD}'10}, booktitle = {{P}roceedings of the 10th {I}nternational {C}onference on {A}pplication of {C}oncurrency to {S}ystem {D}esign ({ACSD}'10)}, author = {Doyen, Laurent and Henzinger, {\relax Th}omas A. and Legay, Axel and Nickovic, Dejan}, title = {Robustness of Sequential Circuits}, pages = {77-84}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DHLN-acsd10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DHLN-acsd10.pdf}, doi = {10.1109/ACSD.2010.26}, abstract = {Digital components play a central role in the design of complex embedded systems. These components are interconnected with other, possibly analog, devices and the physical environment. This environment cannot be entirely captured and can provide inaccurate input data to the component. It~is thus important for digital components to have a robust behavior, \textit{i.e.},~the presence of a small change in the input sequences should not result in a drastic change in the output sequences.\par In this paper, we study a notion of robustness for sequential circuits. However, since sequential circuits may have parts that are naturally discontinuous (\textit{e.g.},~digital controllers with switching behavior), we~need a flexible framework that accommodates this fact and leaves discontinuous parts of the circuit out from the robustness analysis. As a consequence, we~consider sequential circuits that have their input variables partitioned into two disjoint sets: control and disturbance variables. Our contributions are (1)~a~definition of robustness for sequential circuits as a form of continuity with respect to disturbance variables, (2)~the~characterization of the exact class of sequential circuits that are robust according to our definition, (3)~an~algorithm to decide whether a sequential circuit is robust or~not.} }

@inproceedings{DDGRT-csl10, address = {Brno, Czech Republic}, month = aug, year = 2010, volume = {6247}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Dawar, Anuj and Veith, Helmut}, acronym = {{CSL}'10}, booktitle = {{P}roceedings of the 19th {A}nnual {EACSL} {C}onference on {C}omputer {S}cience {L}ogic ({CSL}'10)}, author = {Degorre, Aldric and Doyen, Laurent and Gentilini, Raffaella and Raskin, Jean-Fran{\c{c}}ois and Toru{\'n}czyk, Szymon}, title = {Energy and Mean-Payoff Games with Imperfect Information}, pages = {260-274}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DDGRT-csl10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DDGRT-csl10.pdf}, doi = {10.1007/978-3-642-15205-4_22}, abstract = {We consider two-player games with imperfect information and quantitative objective. The game is played on a weighted graph with a state space partitioned into classes of indistinguishable states, giving players partial knowledge of the state. In an energy game, the weights represent resource consumption and the objective of the game is to maintain the sum of weights always nonnegative. In a mean-payoff game, the objective is to optimize the limit-average usage of the resource. We show that the problem of determining if an energy game with imperfect information with fixed initial credit has a winning strategy is decidable, while the question of the existence of some initial credit such that the game has a winning strategy is undecidable. This undecidability result carries over to mean-payoff games with imperfect information. On the positive side, using a simple restriction on the game graph (namely, that the weights are visible), we show that these problems become EXPTIME-complete.} }

@inproceedings{PhS-mfcs10, address = {Brno, Czech Republic}, month = aug, year = 2010, volume = 6281, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Hlin{\v e}n{\'y}, Petr and Ku{\v c}era, Anton{\'\i}n}, acronym = {{MFCS}'10}, booktitle = {{P}roceedings of the 35th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'10)}, author = {Schnoebelen, {\relax Ph}ilippe}, title = {Revisiting {A}ckermann-Hardness for Lossy Counter Machines and Reset {P}etri Nets}, pages = {616-628}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/phs-mfcs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/phs-mfcs10.pdf}, doi = {10.1007/978-3-642-15155-2_54}, abstract = {We prove that coverability and termination are not primitive-recursive for lossy counter machines and for Reset Petri nets.} }

@inproceedings{CDGH-mfcs10, address = {Brno, Czech Republic}, month = aug, year = 2010, volume = 6281, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Hlin{\v e}n{\'y}, Petr and Ku{\v c}era, Anton{\'\i}n}, acronym = {{MFCS}'10}, booktitle = {{P}roceedings of the 35th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'10)}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Gimbert, Hugo and Henzinger, {\relax Th}omas A.}, title = {Randomness for Free}, pages = {246-257}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDGH-mfcs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDGH-mfcs10.pdf}, doi = {10.1007/978-3-642-15155-2_23}, abstract = {We consider two-player zero-sum games on graphs. These games can be classified on the basis of the information of the players and on the mode of interaction between them. On the basis of information the classification is as follows: (a)~partial-observation (both players have partial view of the game); (b)~one-sided complete-observation (one player has complete observation); and (c)~complete-observation (both players have complete view of the game). On~the basis of mode of interaction we have the following classification: (a)~concurrent (players interact simultaneously); and (b)~turn-based (players interact in turn). The~two sources of randomness in these games are randomness in transition function and randomness in strategies. In general, randomized strategies are more powerful than deterministic strategies, and randomness in transitions gives more general classes of games. We~present a complete characterization for the classes of games where randomness is not helpful~in: (a)~the~transition function (probabilistic transition can be simulated by deterministic transition); and (b)~strategies (pure strategies are as powerful as randomized strategies). As~consequence of our characterization we obtain new undecidability results for these games.} }

@inproceedings{CDH-mfcs10, address = {Brno, Czech Republic}, month = aug, year = 2010, volume = 6281, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Hlin{\v e}n{\'y}, Petr and Ku{\v c}era, Anton{\'\i}n}, acronym = {{MFCS}'10}, booktitle = {{P}roceedings of the 35th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'10)}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Henzinger, {\relax Th}omas A.}, title = {Qualitative Analysis of Partially-observable {M}arkov Decision Processes}, pages = {258-269}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDH-mfcs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDH-mfcs10.pdf}, doi = {10.1007/978-3-642-15155-2_24}, abstract = {We study observation-based strategies for partially-observable Markov decision processes (POMDPs) with parity objectives. An~observation-based strategy relies on partial information about the history of a play, namely, on the past sequence of observations. We~consider qualitative analysis problems: given a POMDP with a parity objective, decide whether there exists an observation-based strategy to achieve the objective with probability~\(1\) (almost-sure winning), or with positive probability (positive winning). Our main results are twofold. First, we present a complete picture of the computational complexity of the qualitative analysis problem for POMDPs with parity objectives and its subclasses: safety, reachability, B{\"u}chi, and coB{\"u}chi objectives. We~establish several upper and lower bounds that were not known in the literature. Second, we give optimal bounds (matching upper and lower bounds) for the memory required by pure and randomized observation-based strategies for each class of objectives.} }

@inproceedings{CDEHR-concur10, address = {Paris, France}, month = aug # {-} # sep, year = 2010, volume = {6269}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Gastin, Paul and Laroussinie, Fran{\c{c}}ois}, acronym = {{CONCUR}'10}, booktitle = {{P}roceedings of the 21st {I}nternational {C}onference on {C}oncurrency {T}heory ({CONCUR}'10)}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Edelsbrunner, Herbert and Henzinger, {\relax Th}omas A. and Rannou, Philippe}, title = {Mean-Payoff Automaton Expressions}, pages = {269-283}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDEHR-concur10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDEHR-concur10.pdf}, doi = {10.1007/978-3-642-15375-4_19}, abstract = {Quantitative languages are an extension of boolean languages that assign to each word a real number. Mean-payoff automata are finite automata with numerical weights on transitions that assign to each infinite path the long-run average of the transition weights. When the mode of branching of the automaton is deterministic, nondeterministic, or alternating, the corresponding class of quantitative languages is not robust as it is not closed under the pointwise operations of max, min, sum, and numerical complement. Nondeterministic and alternating mean-payoff automata are not decidable either, as the quantitative generalization of the problems of universality and language inclusion is undecidable. We introduce a new class of quantitative languages, defined by mean-payoff automaton expressions, which is robust and decidable: it is closed under the four pointwise operations, and we show that all decision problems are decidable for this class. Mean-payoff automaton expressions subsume deterministic mean-payoff automata, and we show that they have expressive power incomparable to nondeterministic and alternating mean-payoff automata. We also present for the first time an algorithm to compute distance between two quantitative languages, and in our case the quantitative languages are given as mean-payoff automaton expressions.} }

@inproceedings{CS-dlt2010, address = {London, Ontario, Canada}, month = aug, year = 2010, volume = {6224}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Gao, Yuan and Lu, Hanlin and Seki, Shinnosuke and Yu, Sheng}, acronym = {{DLT}'10}, booktitle = {{P}roceedings of the 14th {I}nternational {C}onference on {D}evelopments in {L}anguage {T}heory ({DLT}'10)}, author = {Chambart, Pierre and Schnoebelen, {\relax Ph}ilippe}, title = {Computing blocker sets for the Regular {P}ost Embedding Problem}, pages = {136-147}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CS-dlt10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CS-dlt10.pdf}, doi = {10.1007/978-3-642-14455-4_14}, abstract = {Blocker and coblocker sets are regular languages involved in the algorithmic solution of the Regular Post Embedding Problem. We investigate the computability of these languages and related decision problems.} }

@inproceedings{Schmitz-acl10, address = {Uppsala, Sweden}, month = jul, year = 2010, publisher = {Association for Computational Linguistics}, acronym = {{ACL}'10}, booktitle = {{P}roceedings of the 48th {A}nnual {M}eeting of the {A}ssociation for {C}omputational {L}inguistics ({ACL}'10)}, author = {Schmitz, Sylvain}, title = {On the Computational Complexity of Dominance Links in Grammatical Formalisms}, pages = {514-524}, url = {http://hal.archives-ouvertes.fr/hal-00482396}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/Schmitz-acl10.pdf}, abstract = {Dominance links were introduced in grammars to model long distance scrambling phenomena, motivating the definition of multiset-valued linear indexed grammars (MLIGs) by Rambow~(1994b), and inspiring quite a few recent formalisms. It~turns out that MLIGs have since been rediscovered and reused in a variety of contexts, and that the complexity of their emptiness problem has become the key to several open questions in computer science. We survey complexity results and open issues on MLIGs and related formalisms, and provide new complexity bounds for some linguistically motivated restrictions.} }

@article{HNS-tcs10, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {H{\'e}am, Pierre-Cyrille and Nicaud, Cyril and Schmitz, Sylvain}, title = {Parametric Random Generation of Deterministic Tree Automata}, year = 2010, volume = 411, number = {38-39}, pages = {3469-3480}, month = aug, url = {http://hal.inria.fr/inria-00511450}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HNS-tcs10.pdf}, doi = {10.1016/j.tcs.2010.05.036}, abstract = {Uniform random generators deliver a simple empirical means to estimate the average complexity of an algorithm. We present a general rejection algorithm that generates sequential letter-to-letter transducers up to isomorphism. We~also propose an original parametric random generation algorithm to produce sequential letter-to-letter transducers with a fixed number of transitions. We~tailor this general scheme to randomly generate deterministic tree walking automata and deterministic top-down tree automata. We~apply our implementation of the generator to the estimation of the average complexity of a deterministic tree walking automata to nondeterministic top-down tree automata construction we also implemented.} }

@inproceedings{CS-icalp10, address = {Bordeaux, France}, month = jul, year = 2010, volume = 6199, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Abramsky, Samson and Meyer{ }auf{ }der{ }Heide, Friedhelm and Spirakis, Paul}, acronym = {{ICALP}'10}, booktitle = {{P}roceedings of the 37th {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'10)~-- {P}art~{II}}, author = {Chambart, Pierre and Schnoebelen, {\relax Ph}ilippe}, title = {Pumping and Counting on the Regular {P}ost Embedding Problem}, pages = {64-75}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CS-icalp10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CS-icalp10.pdf}, doi = {10.1007/978-3-642-14162-1_6}, abstract = {The Regular Post Embedding Problem is a variant of Post's Correspondence Problem where one compares strings with the subword relation and imposes additional regular constraints on admissible solutions. It is known that this problem is decidable, albeit with very high complexity.\par We consider and solve variant problems where the set of solutions is compared to regular constraint sets and where one counts the number of solutions. Our positive results rely on two non-trivial pumping lemmas for Post-embedding languages and their complements.} }

@inproceedings{CD-icalp10, address = {Bordeaux, France}, month = jul, year = 2010, volume = 6199, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Abramsky, Samson and Meyer{ }auf{ }der{ }Heide, Friedhelm and Spirakis, Paul}, acronym = {{ICALP}'10}, booktitle = {{P}roceedings of the 37th {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'10)~-- {P}art~{II}}, author = {Chatterjee, Krishnendu and Doyen, Laurent}, title = {Energy Parity Games}, pages = {599-610}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-icalp10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-icalp10.pdf}, doi = {10.1007/978-3-642-14162-1_50}, abstract = {Energy parity games are infinite two-player turn-based games played on weighted graphs. The objective of the game combines a (qualitative) parity condition with the (quantitative) requirement that the sum of the weights (\textit{i.e.}, the level of energy in the game) must remain positive. Beside their own interest in the design and synthesis of resource-constrained omega-regular specifications, energy parity games provide one of the simplest model of games with combined qualitative and quantitative objective. Our main results are as follows: (a)~exponential memory is sufficient and may be necessary for winning strategies in energy parity games; (b)~the~problem of deciding the winner in energy parity games can be solved in NP\(\cap\)coNP; and (c)~we~give an algorithm to solve energy parity by reduction to energy games. We~also show that the problem of deciding the winner in energy parity games is polynomially equivalent to the problem of deciding the winner in mean-payoff parity games, which can thus be solved in NP\(\cap\)coNP. As~a consequence we also obtain a conceptually simple algorithm to solve mean-payoff parity games.} }

@article{DLS-tcs10, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Demri, St{\'e}phane and Lazi{\'c}, Ranko and Sangnier, Arnaud}, title = {Model checking memoryful linear-time logics over one-counter automata}, year = {2010}, volume = {411}, number = {22-24}, pages = {2298-2316}, month = may, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DLS-tcs10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DLS-tcs10.pdf}, doi = {10.1016/j.tcs.2010.02.021}, abstract = {We study complexity of the model-checking problems for LTL with registers (also known as freeze LTL and written LTL\(^{\downarrow}\)) and for first-order logic with data equality tests (written \(\textrm{FO}(\sim, <, +1)\)) over one-counter automata. We consider several classes of one-counter automata (mainly deterministic vs. nondeterministic) and several logical fragments (restriction on the number of registers or variables and on the use of propositional variables for control states). The logics have the ability to store a counter value and to test it later against the current counter value. We show that model checking LTL\(^{\downarrow}\) and \(\textrm{FO}(\sim , <, +1)\) over deterministic one-counter automata is PSpace-complete with infinite and finite accepting runs. By constrast, we prove that model checking LTL\(^{\downarrow}\) in which the until operator~\(\mathbf{U}\) is restricted to the eventually~\(\mathbf{F}\) over nondeterministic one-counter automata is \(\Sigma_1^1\)-complete [resp. \(\Sigma_1^0\)-complete] in the infinitary [resp. finitary] case even if only one register is used and with no propositional variable. As a corollary of our proof, this also holds for \(\textrm{FO}(\sim, <, +1)\) restricted to two variables (written \(\textrm{FO}_2 (\sim, <, +1)\)). This makes a difference with the facts that several verification problems for one-counter automata are known to be decidable with relatively low complexity, and that finitary satisfiability for LTL\(^{\downarrow}\) and \(\textrm{FO}_2 (\sim, <, +1)\) are decidable. Our results pave the way for model-checking memoryful (linear-time) logics over other classes of operational models, such as reversal-bounded counter machines.} }

@article{CDH-tocl10, publisher = {ACM Press}, journal = {ACM Transactions on Computational Logic}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Henzinger, {\relax Th}omas A.}, title = {Quantitative Languages}, volume = 11, number = 4, nopages = {}, year = 2010, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDH-tocl10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDH-tocl10.pdf}, ps = {CDH-tocl10.ps}, abstract = {Quantitative generalizations of classical languages, which assign to each word a real number in- stead of a boolean value, have applications in modeling resource-constrained computation. We use weighted automata (finite automata with transition weights) to define several natural classes of quantitative languages over finite and infinite words; in particular, the real value of an infinite run is computed as the maximum, limsup, liminf, limit average, or discounted sum of the transition weights. We define the classical decision problems of automata theory (emptiness, universality, language inclusion, and language equivalence) in the quantitative setting and study their compu- tational complexity. As the decidability of the language-inclusion problem remains open for some classes of weighted automata, we introduce a notion of quantitative simulation that is decidable and implies language inclusion. We also give a complete characterization of the expressive power of the various classes of weighted automata. In particular, we show that most classes of weighted automata cannot be determinized.} }

@inproceedings{DR-tacas10, address = {Paphos, Cyprus}, month = mar, year = 2010, volume = {6015}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Esparza, Javier and Majumdar, Rupak}, acronym = {{TACAS}'10}, booktitle = {{P}roceedings of the 16th {I}nternational {C}onference on {T}ools and {A}lgorithms for {C}onstruction and {A}nalysis of {S}ystems ({TACAS}'10)}, author = {Doyen, Laurent and Raskin, Jean-Fran{\c{c}}ois}, title = {Antichains Algorithms for Finite Automata}, pages = {2-22}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DR-tacas10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DR-tacas10.pdf}, ps = {DR-tacas10.ps}, doi = {10.1007/978-3-642-12002-2_2}, abstract = {We present a general theory that exploits simulation relations on transition systems to obtain antichain algorithms for solving the reachability and repeated reachability problems. Antichains are more succinct than the sets of states manipulated by the traditional fixpoint algorithms. The theory justifies the correctness of the antichain algorithms, and applications such as the universality problem for finite automata illustrate efficiency improvements. Finally, we show that new and provably better antichain algorithms can be obtained for the emptiness problem of alternating automata over finite and infinite words.} }

@article{BCDDH-icomp10, publisher = {Elsevier Science Publishers}, journal = {Information and Computation}, author = {Berwanger, Dietmar and Chatterjee, Krishnendu and Doyen, Laurent and De{~}Wulf, Martin and Henzinger, {\relax Th}omas A.}, title = {Strategy Construction for Parity Games with Imperfect Information}, volume = 208, number = 10, pages = {1206-1220}, year = 2010, month = oct, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BCDDH-icomp10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BCDDH-icomp10.pdf}, ps = {BCDDH-icomp10.ps}, doi = {10.1016/j.ic.2009.09.006}, abstract = {We consider two-player parity games with imperfect information in which strategies rely on observations that provide imperfect information about the history of a play. To solve such games, \textit{i.e.}, to determine the winning regions of players and corresponding winning strategies, one can use the subset construction to build an equivalent perfect-information game. Recently, an algorithm that avoids the inefficient subset construction has been proposed. The algorithm performs a fixed-point computation in a lattice of antichains, thus maintaining a succinct representation of state sets. However, this representation does not allow to recover winning strategies.\par In this paper, we build on the antichain approach to develop an algorithm for constructing the winning strategies in parity games of imperfect information. One major obstacle in adapting the classical procedure is that the complementation of attractor sets would break the invariant of downward-closedness on which the antichain representation relies. We overcome this difficulty by decomposing problem instances recursively into games with a combination of reachability, safety, and simpler parity conditions. We also report on an experimental implementation of our algorithm; to our knowledge, this is the first implementation of a procedure for solving imperfect-information parity games on graphs.} }

@misc{averiles09-f2.2, author = {LIAFA and CRIL and EDF and LSV and Verimag}, title = {Projet {RNTL} {A}veriles~-- Fourniture F2.2~: Algorithmes de v{\'e}rification~-- Rapport final}, year = 2009, month = nov, type = {Contract Report}, note = {25~pages}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/averiles-f22.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/averiles-f22.pdf} }

@inproceedings{ltc-GardentPPS11, address = {Pozna\'n, Poland}, month = nov, year = 2014, volume = {8387}, series = {Lecture Notes in Artificial Intelligence}, publisher = {Springer}, editor = {Vetulani, Zygmunt and Mariani, Joseph}, acronym = {{LTC}'11}, booktitle = {{P}roceedings of the 5th {L}anguage {\&} {T}echnology {C}onference ({LTC}'11)}, author = {Gardent, Claire and Perrier, Guy and Parmentier, Yannick and Schmitz, Sylvain}, title = {Lexical Disambiguation in {LTAG} using Left Context}, nopages = {}, url = {http://hal.archives-ouvertes.fr/hal-00629902/}, abstract = {In this paper, we present an automaton-based lexical disambiguation process for Lexicalized Tree-Adjoining Grammar (LTAG). This process builds on previous work of Bonfante \textit{et~al.}~(2004), and extends it by computing a polarity-based abstraction, which contains information about left context. This extension allows for a faster lexical disambiguation by reducing the filtering automaton.} }

@inproceedings{DMS-iwigp11, address = {Saarbr{\"u}cken, Germany}, month = mar, year = 2011, volume = 50, series = {Electronic Proceedings in Theoretical Computer Science}, editor = {Reich, Johannes and Finkbeiner, Bernd}, acronym = {{iWIGP}'11}, booktitle = {{P}roceedings of the {I}nternational {W}orkshop on {I}nteractions, {G}ames and {P}rotocols ({iWIGP}'11)}, author = {Doyen, Laurent and Massart, {\relax Th}ierry and Shirmohammadi, Mahsa}, title = {Synchronizing Objectives for {M}arkov Decision Processes}, pages = {61-75}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DMS-iwigp11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DMS-iwigp11.pdf} }

@inproceedings{CD-memics11, address = {Lednice, Czech Republic }, month = oct, year = 2011, volume = 7119, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Bouda, Jan and {\v{C}}ern{\'a}, Ivana and Sekanina, Luk{\'a}{\v{s}} and Vojnar, Tom{\'a}{\v{s}}}, acronym = {{MEMICS}'11}, booktitle = {{P}roceedings of the 7th {A}nnual {D}octoral {W}orkshop on {M}athematical and {E}ngineering {M}ethods in {C}omputer {S}cience ({MEMICS}'11)}, author = {Chatterjee, Krishnendu and Doyen, Laurent}, title = {Games and Markov Decision Processes with Mean-payoff Parity and Energy Parity Objectives}, nopages = {}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-memics11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-memics11.pdf}, abstract = {The analysis of games and probabilistic systems with quantitative objectives (such as mean-payoff and energy objectives) and \(\omega\)-regular objectives (such as parity objectives) provide the mathematical foundation for performance analysis and verification of various classes of systems. In this talk, we will present a survey of both classical results and recent results about mean-payoff, energy, and parity objectives. We will discuss about how to solve their combinations, their inter-relationship, and mention interesting open problems.} }

@inproceedings{BBDDR-atva11, address = {Taipei, Taiwan}, month = oct, year = {2011}, volume = 6996, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Bultan, Tevfik and Hsiung, Pao-Ann}, acronym = {{ATVA}'11}, booktitle = {{P}roceedings of the 9th {I}nternational {S}ymposium on {A}utomated {T}echnology for {V}erification and {A}nalysis ({ATVA}'11)}, author = {Brihaye, {\relax Th}omas and Bruy{\`e}re, V{\'e}ronique and Doyen, Laurent and Ducobu, Marc and Raskin, Jean-Fran{\c{c}}ois}, title = {Antichain-based {QBF} Solving}, pages = {183-197}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BBDDR-atva11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BBDDR-atva11.pdf}, doi = {10.1007/978-3-642-24372-1_14} }

@article{BCDGR-fmsd2011, publisher = {Springer}, journal = {Formal Methods in System Design}, author = {Brim, Lubos and Chaloupka, Jakub and Doyen, Laurent and Gentilini, Raffaella and Raskin, Jean-Fran{\c{c}}ois}, title = {Faster algorithms for mean-payoff games}, year = {2011}, month = apr, volume = {38}, number = {2}, pages = {97-118}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BCDGR-fmsd2011.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BCDGR-fmsd2011.pdf}, doi = {10.1007/s10703-010-0105-x} }

@article{FG-lmcs12, journal = {Logical Methods in Computer Science}, author = {Finkel, Alain and Goubault{-}Larrecq, Jean}, title = {Forward Analysis for {WSTS}, Part~{II}: Complete {WSTS}}, year = 2012, month = sep, volume = 8, number = {3:28}, nopages = {}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/FG-lmcs12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/FG-lmcs12.pdf}, doi = {10.2168/LMCS-8(3:28)2012}, abstract = {We describe a simple, conceptual forward analysis procedure for \(\infty\)-complete WSTS~\(\mathfrak{S}\). This computes the so-called \emph{clover} of a state. When \(\mathfrak{S}\) is the completion of a WSTS~\(\mathfrak{X}\), the clover in~\(\mathfrak{S}\) is a finite description of the downward closure of the reachability set. We show that such completions are infinity-complete exactly when \(\mathfrak{X}\) is an \(\omega^2\)-WSTS, a~new robust class of WSTS. We show that our procedure terminates in more cases than the generalized Karp-Miller procedure on extensions of Petri nets and on lossy channel systems. We characterize the WSTS where our procedure terminates as those that are \emph{clover-flattable}. Finally, we apply this to well-structured counter systems.} }

@techreport{lsv-11-23, author = {Lozes, {\'E}tienne and Villard, Jules}, title = {Sharing Contract-Obedient Endpoints}, institution = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, year = {2011}, month = dec, type = {Research Report}, number = {LSV-11-23}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/rr-lsv-2011-23.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/rr-lsv-2011-23.pdf}, versions = {http://www.lsv.fr/Publis/PAPERS/PDF/rr-lsv-2011-23-v1.pdf, 20111207}, note = {42~pages}, abstract = {Most of the existing verification techniques for programs based on message passing suppose either that channel endpoints are used in a linear fashion, where at most one thread can be considered as the owner of an endpoint at any given time, or that endpoints may be used arbitrarily by any number of threads. The former approach forbids the sharing of channels, while the latter limits what is provable about programs, since no constraint is put on the usage of channels. In this paper, we propose a midpoint between these techniques by extending a previously published proof system based on separation logic to allow the sharing of endpoints. We identify two independent mechanisms for supporting sharing: the standard technique based on reasoning with permissions, and a new technique based on what we call ownership on demand. We formalize these two techniques in a proof system, illustrate them on several examples, and we extend Villard's semantics and soundness proofs to support sharing.} }

@phdthesis{chambart-phd2011, author = {Chambart, Pierre}, title = {Du Probl{\`e}me de sous-mot de {P}ost et de la complexit{\'e} des canaux non fiables}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, type = {Th{\`e}se de doctorat}, year = 2011, month = sep, url = {http://www.lsv.fr/Publis/PAPERS/PDF/chambart-these11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/chambart-these11.pdf} }

@inproceedings{CFM-ncma11, address = {Milano, Italy}, month = jul, year = 2011, volume = 282, series = {books@ocg.at}, publisher = {Austrian Computer Society}, editor = {Freund, Rudolf and Holzer, Markus and Mereghetti, Carlo and Otto, Friedrich and Palano, Beatrice}, acronym = {{NCMA}'11}, booktitle = {{P}roceedings of the 3rd {W}orkshop on {N}on-{C}lassical {M}odels of {A}utomata and {A}pplications ({NCMA}'11)}, author = {Cadilhac, Micha{\"e}l and Finkel, Alain and McKenzie, Pierre}, title = {On the Expressiveness of {P}arikh Automata and Related Models}, pages = {103-119}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-ncma11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-ncma11.pdf}, doi = {} }

@inproceedings{CFM-words11, address = {Prague, Czech Republic}, month = sep, year = 2011, volume = {63}, series = {Electronic Proceedings in Theoretical Computer Science}, editor = {Ambro{\v{z}}, Petr and Holub, {\v{S}}t{\v{e}}p{\'a}n and Mas{\'a}kov{\'a}, Zuzana}, acronym = {{WORDS}'11}, booktitle = {{P}roceedings of the 8th {I}nternational {C}onference {WORDS} ({WORDS}'11)}, author = {Cadilhac, Micha{\"e}l and Finkel, Alain and McKenzie, Pierre}, title = {Bounded {P}arikh Automata}, pages = {93-102}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-words11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-words11.pdf}, doi = {10.4204/EPTCS.63.13} }

@inproceedings{CDS-fct11, address = {Oslo, Norway}, month = aug, year = 2011, volume = 6914, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Owe, Olaf and Steffen, Martin and Telle, Jan Arne}, acronym = {{FCT}'11}, booktitle = {{P}roceedings of the 18th {I}nternational {S}ymposium on {F}undamentals of {C}omputation {T}heory ({FCT}'11)}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Singh, Rohit}, title = {On Memoryless Quantitative Objectives}, pages = {148-159}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDS-fct11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDS-fct11.pdf}, doi = {10.1007/978-3-642-22953-4_13}, abstract = {In two-player games on graph, the players construct an infinite path through the game graph and get a reward computed by a payoff function over infinite paths. Over weighted graphs, the typical and most studied payoff functions compute the limit-average or the discounted sum of the rewards along the path. Besides their simple definition, these two payoff functions enjoy the property that memoryless optimal strategies always exist.\par In an attempt to construct other simple payoff functions, we define a class of payoff functions which compute an (infinite) weighted average of the rewards. This new class contains both the limit-average and the discounted sum functions, and we show that they are the only members of this class which induce memoryless optimal strategies, showing that there is essentially no other simple payoff functions.} }

@incollection{DP-DS11b, author = {Demri, St{\'e}phane and Poitrenaud, Denis}, title = {Verification of Infinite-State Systems}, booktitle = {Models and Analysis in Distributed Systems}, editor = {Haddad, Serge and Kordon, Fabrice and Pautet, Laurent and Petrucci, Laure}, publisher = {John Wiley \& Sons, Ltd.}, chapter = 8, pages = {221-269}, year = 2011, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DP-DS11b.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DP-DS11b.pdf} }

@inproceedings{bonnet-RP11, address = {Genova, Italy}, month = sep, year = 2011, volume = {6945}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Delzanno, Giorgio and Potapov, Igor}, acronym = {{RP}'11}, booktitle = {{P}roceedings of the 5th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'11)}, author = {Bonnet, R{\'e}mi}, title = {Decidability of {LTL} Model Checking for Vector Addition Systems with one Zero-test}, pages = {85-95}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/bonnet-RP11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/bonnet-RP11.pdf}, doi = {10.1007/978-3-642-24288-5_9}, abstract = {We consider the class of Vector Addition Systems with one zero-test and we show that the model-checking problem for LTL is decidable thanks to a reduction to the computability of the cover and the decidability of reachability. Our proof uses the notion of increasing loop, that we refine to fit the non-standard monotony of our system.} }

@inproceedings{CD-mfcs11, address = {Warsaw, Poland}, month = aug, year = 2011, volume = 6907, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Murlak, Filip and Sankowski, Piotr}, acronym = {{MFCS}'11}, booktitle = {{P}roceedings of the 36th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'11)}, author = {Chatterjee, Krishnendu and Doyen, Laurent}, title = {Energy and Mean-Payoff Parity {M}arkov Decision Processes}, pages = {206-218}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-mfcs11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-mfcs11.pdf}, doi = {10.1007/978-3-642-22993-0_21}, abstract = {We consider Markov Decision Processes (MDPs) with mean-payoff parity and energy parity objectives. In system design, the parity objective is used to encode \(\omega\)-regular specifications, while the mean-payoff and energy objectives can be used to model quantitative resource constraints. The energy condition requires that the resource level never drops below~\(0\), and the mean-payoff condition requires that the limit-average value of the resource consumption is within a threshold. While these two (energy and mean-payoff) classical conditions are equivalent for two-player games, we~show that they differ for MDPs. We show that the problem of deciding whether a state is almost-sure winning (i.e., winning with probability~\(1\)) in energy parity MDPs is in \(\textsf{NP}\cap\textsf{coNP}\), while for mean-payoff parity MDPs, the problem is solvable in polynomial time.} }

@inproceedings{DMS-mfcs11, address = {Warsaw, Poland}, month = aug, year = 2011, volume = 6907, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Murlak, Filip and Sankowski, Piotr}, acronym = {{MFCS}'11}, booktitle = {{P}roceedings of the 36th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'11)}, author = {Doyen, Laurent and Massart, {\relax Th}ierry and Shirmohammadi, Mahsa}, title = {Infinite Synchronizing Words for Probabilistic Automata}, pages = {278-289}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DMS-mfcs11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DMS-mfcs11.pdf}, doi = {10.1007/978-3-642-22993-0_27}, abstract = {Probabilistic automata are finite-state automata where the transitions are chosen according to fixed probability distributions. We consider a semantics where on an input word the automaton produces a sequence of probability distributions over states. An~infinite word is accepted if the produced sequence is synchronizing, i.e. the sequence of the highest probability in the distributions tends to~\(1\). We show that this semantics generalizes the classical notion of synchronizing words for deterministic automata. We consider the emptiness problem, which asks whether some word is accepted by a given probabilistic automaton, and the universality problem, which asks whether all words are accepted. We provide reductions to establish the PSPACE-completeness of the two problems.} }

@inproceedings{Schmitz-fsmnlp11, address = {Blois, France}, month = jul, year = 2011, publisher = {ACL Press}, editor = {Maletti, Andreas}, acronym = {{FSMNLP}'11}, booktitle = {{P}roceedings of the 9th {I}nternational {W}orkshop on {F}inite-{S}tate {M}ethods and {N}atural {L}anguage {P}rocessing ({FSMNLP}'11)}, author = {Sylvain Schmitz}, title = {A~Note on Sequential Rule-Based {POS} Tagging}, pages = {83-87}, url = {http://hal.archives-ouvertes.fr/hal-00600260/}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/Schmitz-fsmnlp11.pdf}, abstract = {Brill's part-of-speech tagger is defined through a cascade of leftmost rewrite rules. We revisit the compilation of such rules into a single sequential transducer given by Roche and Schabes (\textit{Comput. Ling.}~1995) and provide a direct construction of the minimal sequential transducer for each individual rule.} }

@inproceedings{BS-mfcs11, address = {Warsaw, Poland}, month = aug, year = 2011, volume = 6907, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Murlak, Filip and Sankowski, Piotr}, acronym = {{MFCS}'11}, booktitle = {{P}roceedings of the 36th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'11)}, author = {Blockelet, Michel and Schmitz, Sylvain}, title = {Model-Checking Coverability Graphs of Vector Addition Systems}, pages = {108-119}, url = {http://hal.archives-ouvertes.fr/hal-00600077/}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BS-mfcs11.pdf}, doi = {10.1007/978-3-642-22993-0_13}, abstract = {A large number of properties of a vector addition system---for instance coverability, boundedness, or regularity---can be decided using its coverability graph, by looking for some characteristic pattern. We propose to unify the known exponential-space upper bounds on the complexity of such problems on vector addition systems, by seeing them as instances of the model-checking problem for a suitable extension of computation tree logic, which allows to check for the existence of these patterns. This provides new insights into what constitutes a {"}coverability-like{"} property.} }

@inproceedings{Bonnet-mfcs11, address = {Warsaw, Poland}, month = aug, year = 2011, volume = 6907, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Murlak, Filip and Sankowski, Piotr}, acronym = {{MFCS}'11}, booktitle = {{P}roceedings of the 36th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'11)}, author = {Bonnet, R{\'e}mi}, title = {The reachability problem for Vector Addition Systems with one zero-test}, pages = {145-157}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/RB-mfcs11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/RB-mfcs11.pdf}, doi = {10.1007/978-3-642-22993-0_16}, abstract = {We consider here a variation of Vector Addition Systems where one counter can be tested for zero. We extend the reachability proof for Vector Addition System recently published by Leroux to this model. This provides an alternate, more conceptual proof of the reachability problem that was originally proved by Reinhardt.} }

@article{DDG-jlc11, publisher = {Oxford University Press}, journal = {Journal of Logic and Computation}, author = {Demri, St{\'e}phane and D'Souza, Deepak and Gascon, R{\'e}gis}, title = {Temporal Logics of Repeating Values}, year = {2012}, month = oct, volume = 22, number = 5, pages = {1059-1096}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DDG-jlc11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DDG-jlc11.pdf}, doi = {10.1093/logcom/exr013}, abstract = {Various logical formalisms with the freeze quantifier have been recently considered to model computer systems even though this is a powerful mechanism that often leads to undecidability. In this paper, we study a linear-time temporal logic with past-time operators such that the freeze operator is only used to express that some value from an infinite set is repeated in the future or in the past. Such a restriction has been inspired by a recent work on spatio-temporal logics that suggests such a restricted use of the freeze operator. We show decidability of finitary and infinitary satisfiability by reduction into the verification of temporal properties in Petri nets by proposing a symbolic representation of models. This is a quite surprising result in view of the expressive power of the logic since the logic is closed under negation, contains future-time and past-time temporal operators and can express the nonce property and its negation. These ingredients are known to lead to undecidability with a more liberal use of the freeze quantifier. The paper also contains developments about the relationships between temporal logics with the freeze operator and counter automata as well as reductions into first-order logics over data words.} }

@inproceedings{BDGORW-icalp11, address = {Z{\"u}rich, Switzerland}, month = jul, year = 2011, volume = 6756, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Aceto, Luca and Henzinger, Monika and Sgall, Jir{\'\i}}, acronym = {{ICALP}'11}, booktitle = {{P}roceedings of the 38th {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'11)~-- {P}art~{II}}, author = {Brihaye, {\relax Th}omas and Doyen, Laurent and Geeraerts, Gilles and Ouaknine, Jo{\"e}l and Raskin, Jean-Fran{\c{c}}ois and Worrell, James}, title = {On~Reachability for Hybrid Automata over Bounded Time}, pages = {416-427}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BDGORW-icalp11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BDGORW-icalp11.pdf}, doi = {10.1007/978-3-642-22012-8_33}, abstract = {This paper investigates the time-bounded version of the reachability problem for hybrid automata. This problem asks whether a given hybrid automaton can reach a given target location within~\(\mathbf{T}\) time units, where \(\mathbf{T}\) is a constant rational value. We show that, in contrast to the classical (unbounded) reachability problem, the timed-bounded version is decidable for rectangular hybrid automata provided only non-negative rates are allowed. This class of systems is of practical interest and subsumes, among others, the class of stopwatch automata. We also show that the problem becomes undecidable if either diagonal constraints or both negative and positive rates are allowed.} }

@inproceedings{SS-icalp11, address = {Z{\"u}rich, Switzerland}, month = jul, year = 2011, volume = 6756, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Aceto, Luca and Henzinger, Monika and Sgall, Jir{\'\i}}, acronym = {{ICALP}'11}, booktitle = {{P}roceedings of the 38th {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'11)~-- {P}art~{II}}, author = {Schmitz, Sylvain and Schnoebelen, {\relax Ph}ilippe}, title = {Multiply-Recursive Upper Bounds with {H}igman's Lemma}, pages = {441-452}, url = {http://arxiv.org/abs/1103.4399}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/SS-icalp11.pdf}, doi = {10.1007/978-3-642-22012-8_35}, abstract = {We develop a new analysis for the length of controlled bad sequences in well-quasi-orderings based on Higman's Lemma. This leads to tight multiply-recursive upper bounds that readily apply to several verification algorithms for well-structured systems.} }

@inproceedings{CFS-atpn2011, address = {Newcastle upon Tyne, UK}, month = jun, year = 2011, volume = {6709}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Kristensen, Lars M. and Petrucci, Laure}, acronym = {{PETRI~NETS}'11}, booktitle = {{P}roceedings of the 32nd {I}nternational {C}onference on {A}pplications and {T}heory of {P}etri {N}ets ({PETRI~NETS}'11)}, author = {Chambart, Pierre and Finkel, Alain and Schmitz, Sylvain}, title = {Forward Analysis and Model Checking for Trace Bounded {WSTS}}, nopages = {49-68}, url = {http://arxiv.org/abs/1004.2802}, doi = {10.1007/978-3-642-21834-7_4}, abstract = {We investigate a subclass of well-structured transition systems~(WSTS), the bounded---in the sense of Ginsburg and Spanier (Trans. AMS 1964)---complete deterministic ones, which we claim provide an adequate basis for the study of forward analyses as developed by Finkel and Goubault-Larrecq (ICALP~2009). Indeed, we prove that, unlike other conditions considered previously for the termination of forward analysis, boundedness is decidable. Boundedness turns out to be a valuable restriction for WSTS verification, as we show that it further allows to decide all \(\omega\)-regular properties on the set of infinite traces of the system.} }

@inproceedings{FFSS-lics2011, address = {Toronto, Canada}, month = jun, year = 2011, publisher = {{IEEE} Computer Society Press}, acronym = {{LICS}'11}, booktitle = {{P}roceedings of the 26th {A}nnual {IEEE} {S}ymposium on {L}ogic in {C}omputer {S}cience ({LICS}'11)}, author = {Figueira, Diego and Figueira, Santiago and Schmitz, Sylvain and Schnoebelen, {\relax Ph}ilippe}, title = {{A}ckermannian and Primitive-Recursive Bounds with {D}ickson's Lemma}, pages = {269-278}, url = {http://arxiv.org/abs/1007.2989}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/FFSS-lics11.pdf}, doi = {10.1109/LICS.2011.39}, abstract = {Dickson's Lemma is a simple yet powerful tool widely used in decidability proofs, especially when dealing with counters or related data structures in algorithmics, verification and model-checking, constraint solving, logic, etc. While Dickson's Lemma is well-known, most computer scientists are not aware of the complexity upper bounds that are entailed by its use. This is mainly because, on this issue, the existing literature is not very accessible.\par We propose a new analysis of the length of bad sequences over \((\mathbb{N}^{k},\leq)\), improving on earlier results and providing upper bounds that are essentially tight. This analysis is complemented by a {"}user guide{"} explaining through practical examples how to easily derive complexity upper bounds from Dickson's Lemma.} }

@phdthesis{villard-phd2010, author = {Villard, Jules}, title = {Heaps and Hops}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, type = {Th{\`e}se de doctorat}, year = 2011, month = feb, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/villard-phd.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/villard-phd.pdf}, abstract = {This thesis is about the specification and verification of copyless message-passing programs, a particular kind of concurrent programs that communicate by message passing. Instead of copying messages over channels, processes exchange pointers into a shared memory where the actual contents of messages are stored. Channels are themselves objects in the heap that can be communicated, thus achieving full mobility. This flexible and efficient programming paradigm must be used carefully: every pointer that is communicated becomes shared between its sender and its recipient, which may introduce races. To err on the side of caution, the sender process should not attempt to access the area of storage circumscribed by a message once it has been sent. Indeed, this right is now reserved to the recipient, who may already have modified it or even disposed of it. In other words, the ownership of pieces of heap hops from process to process following the flow of messages.\par Copyless message passing combines two features of programs that make formal verification challenging: explicit memory management and concurrency. To tackle these difficulties, we base our approach on two recent developments. On the one hand, concurrent separation logic produces concise proofs of pointer-manipulating programs by keeping track only of those portions of storage owned by the program. We use such local reasoning techniques to analyse the fluxes of ownership in programs, and ensure in particular that no dangling pointer will be dereferenced or freed at runtime. On the other hand, channel contracts, a form of session types introduced by the Sing\# programming language, provide an abstraction of the exchanges of messages that can be used to statically verify that programs never face unexpected message receptions and that all messages are delivered before a channel is closed.\par The contributions contained in this thesis fall into three categories. First, we give a semantics to copyless message-passing programs, the ownership transfers they induce and contracts, and link the three together. In doing so, we provide the first formal model of a theoretically significant subset of the Sing\# programming language. In particular, we show that some properties of their contracts rub off on programs, which justifies their use as protocol specifications. Second, we introduce the first proof system for copyless message passing, based on separation logic and contracts. The proof system discharges parts of the verification of programs on the verification of their contracts. The marriage of these two techniques allows one to prove that programs are free from memory faults, race conditions and message-passing errors such as unspecified receptions and undelivered messages. Moreover, we show how the logic and contracts cooperate to prove the absence of memory leaks. Third, we give an implementation of our analysis, Heap-Hop, that takes annotated programs as input and automatically checks the given specifications and deduces which of the properties above are enjoyed by the program. The only annotations needed by Heap-Hop are pre and postconditions of each function, loop invariants, and the contracts followed by the communications.} }

@article{DFGD-jancl10, publisher = {Taylor \& Francis}, journal = {Journal of Applied Non-Classical Logics}, author = {Demri, St{\'e}phane and Finkel, Alain and Goranko, Valentin and van Drimmelen, Govert}, title = {Model-checking \(\textsf{CTL}^{*}\) over Flat {P}resburger Counter Systems}, year = {2010}, volume = {20}, number = {4}, pages = {313-344}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DFGD-jancl10.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DFGD-jancl10.pdf}, doi = {10.3166/jancl.20.313-344}, abstract = {This paper studies model-checking of fragments and extensions of \(\textsf{CTL}^{*}\) on infinite-state counter systems, where the states are vectors of integers and the transitions are determined by means of relations definable within Presburger arithmetic. In general, reachability properties of counter systems are undecidable, but we have identified a natural class of admissible counter systems (ACS) for which we show that the quantification over paths in \(\textsf{CTL}^{*}\) can be simulated by quantification over tuples of natural numbers, eventually allowing translation of the whole Presburger-\(\textsf{CTL}^{*}\) into Presburger arithmetic, thereby enabling effective model checking. We provide evidence that our results are close to optimal with respect to the class of counter systems described above.} }

@inproceedings{JLTV-tosca11, address = {Saarbr{\"u}cken, Germany}, month = jan, year = 2012, volume = 6993, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {M{\"o}dersheim, Sebastian A. and Palamidessi, Catuscia}, acronym = {{TOSCA}'11}, booktitle = {{R}evised {S}elected {P}apaers of the {W}orkshop on {T}heory of {S}ecurity and {A}pplications ({TOSCA}'11)}, author = {Jacquemard, Florent and Lozes, {\'E}tienne and Treinen, Ralf and Villard, Jules}, title = {Multiple Congruence Relations, First-Order Theories on Terms, and the Frames of the Applied Pi-Calculus}, pages = {166-185}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/JLTV-tosca11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/JLTV-tosca11.pdf}, doi = {10.1007/978-3-642-27375-9_10}, abstract = {We investigate the problem of deciding first-order theories of finite trees with several distinguished congruence relations, each of them given by some equational axioms. We give an automata-based solution for the case where the different equational axiom systems are linear and variable-disjoint (this includes the case where all axioms are ground), and where the logic does not permit to express tree relations \(x=f(y,z)\). We~show that the problem is undecidable when these restrictions are relaxed. As motivation and application, we show how to translate the model-checking problem of \(A\pi\mathcal{L}\), a~spatial equational logic for the applied pi-calculus, to the validity of first-order formulas in term algebras with multiple congruence relations.} }

@inproceedings{BFHR-fossacs11, address = {Saarbr{\"u}cken, Germany}, month = mar # {-} # apr, year = 2011, volume = {6604}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Hofmann, Martin}, acronym = {{FoSSaCS}'11}, booktitle = {{P}roceedings of the 14th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'11)}, author = {Bonnet, R{\'e}mi and Finkel, Alain and Haddad, Serge and Rosa{-}Velardo, Fernando}, title = {Ordinal Theory for Expressiveness of Well Structured Transition Systems}, pages = {153-167}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BFHR-fossacs11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BFHR-fossacs11.pdf}, doi = {10.1007/978-3-642-19805-2_11} }

@incollection{DG-iis09, author = {Demri, St{\'e}phane and Gastin, Paul}, title = {Specification and Verification using Temporal Logics}, booktitle = {Modern applications of automata theory}, editor = {D'Souza, Deepak and Shankar, Priti}, series = {IISc Research Monographs}, volume = 2, publisher = {World Scientific}, chapter = 15, pages = {457-494}, year = 2012, month = jul, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DG-iis09.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DG-iis09.pdf}, abstract = {This chapter illustrates two aspects of automata theory related to linear-time temporal logic LTL used for the verification of computer systems. First, we present a translation from LTL formulae to B{\"u}chi automata. The aim is to design an elementary translation which is reasonably efficient and produces small automata so that it can be easily taught and used by hand on real examples. Our translation is in the spirit of the classical tableau constructions but is optimized in several ways. Secondly, we recall how temporal operators can be defined from regular languages and we explain why adding even a single operator definable by a context-free language can lead to undecidability.} }

@article{BFHR-icomp13, publisher = {Elsevier Science Publishers}, journal = {Information and Computation}, author = {Bonnet, R{\'e}mi and Finkel, Alain and Haddad, Serge and Rosa{-}Velardo, Fernando}, title = {Ordinal Theory for Expressiveness of Well-Structured Transition Systems}, year = 2013, month = mar, volume = 224, pages = {1-22}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BFHR-icomp12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BFHR-icomp12.pdf}, doi = {10.1016/j.ic.2012.11.003}, abstract = {We characterize the importance of resources (like counters, channels, or alphabets) when measuring the expressiveness of Well-Structured Transition Systems~(WSTS). We establish, for usual classes of well partial orders, the equivalence between the existence of order reflections (non-monotonic order embeddings) and the simulations with respect to coverability languages. We show that the non-existence of order reflections can be proved by the computation of order types. This allows us to extend the current classification of WSTS, in particular solving some open problems, and to unify the existing proofs.} }

@article{CFM-ijfcs12, publisher = {World Scientific}, journal = {International Journal of Foundations of Computer Science}, author = {Cadilhac, Micha{\"e}l and Finkel, Alain and McKenzie, Pierre}, title = {Bounded {P}arikh automata}, year = 2012, month = dec, volume = {23}, number = {8}, pages = {1691-1710}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-ijfcs12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-ijfcs12.pdf}, doi = {10.1142/S0129054112400709}, abstract = {The Parikh finite word automaton model~(PA) was introduced and studied by Klaedtke and Rue{\ss}. Here, we present some expressiveness properties of a restriction of the deterministic affine PA recently introduced, and use them as a tool to show that the bounded languages recognized by PA are the same as those recognized by deterministic PA. Moreover, this class of languages is shown equal to the class of bounded languages with a semilinear iteration set.} }

@article{CFM-rairo12, address = {Les Ulis, France}, publisher = {EDP Sciences}, journal = {RAIRO Informatique Th{\'e}orique et Applications}, author = {Cadilhac, Micha{\"e}l and Finkel, Alain and McKenzie, Pierre}, title = {Affine {P}arikh automata}, year = 2012, month = oct, volume = 46, number = 4, pages = {511-545}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-rairo12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-rairo12.pdf}, doi = {10.1051/ita/2012013}, abstract = {The Parikh finite word automaton (PA) was introduced and studied in 2003 by Klaedtke and Rue\ss. Natural variants of the PA arise from viewing a PA equivalently as an automaton that keeps a count of its transitions and semilinearly constrains their numbers. Here we adopt this view and define the affine PA, that extends the PA by having each transition induce an affine transformation on the PA registers, and the PA on letters, that restricts the PA by forcing any two transitions on the same letter to affect the registers equally. Then we report on the expressiveness, closure, and decidability properties of such PA variants. We note that deterministic PA are strictly weaker than deterministic reversal-bounded counter machines.} }

@inproceedings{CFM-dlt12, address = {Taipei, Taiwan}, month = aug, year = 2012, volume = 7410, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Yen, Hsu-Chun and Ibarra, Oscar H.}, acronym = {{DLT}'12}, booktitle = {{P}roceedings of the 16th {I}nternational {C}onference on {D}evelopments in {L}anguage {T}heory ({DLT}'12)}, author = {Cadilhac, Micha{\"e}l and Finkel, Alain and McKenzie, Pierre}, title = {Unambiguous Constrained Automata}, pages = {239-250}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-dlt12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CFM-dlt12.pdf}, doi = {10.1007/978-3-642-31653-1_22}, abstract = {The class of languages captured by Constrained Automata~(CA) that are unambiguous is shown to possess more closure properties than the provably weaker class captured by deterministic~CA. Problems decidable for deterministic CA are nonetheless shown to remain decidable for unambiguous CA, and testing for \emph{regularity} is added to this set of decidable problems. Unambiguous CA are then shown incomparable with deterministic reversal-bounded machines in terms of expressivity, and a \emph{deterministic} model equivalent to unambiguous CA is identified.} }

@article{DDMM-lmcs12, journal = {Logical Methods in Computer Science}, author = {Darondeau, {\relax Ph}ilippe and Demri, St{\'e}phane and Meyer, Roland and Morvan, {\relax Ch}ristophe}, title = {{P}etri Net Reachability Graphs: Decidability Status of {FO} Properties}, volume = 8, number = {4:9}, nopages = {}, month = oct, year = 2012, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DDMM-lmcs12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DDMM-lmcs12.pdf}, doi = {10.2168/LMCS-8(4:9)2012}, abstract = {We investigate the decidability and complexity status of model-checking problems on unlabelled reachability graphs of Petri nets by considering first-order and modal languages without labels on transitions or atomic propositions on markings. We consider several parameters to separate decidable problems from undecidable ones. Not only are we able to provide precise borders and a systematic analysis, but we also demonstrate the robustness of our proof techniques.} }

@misc{verydic-d2, author = {Iosif, Radu and Habermehl, Peter and Labbe, Sebastien and Lozes, {\'E}tienne and Yakobowski, Boris}, title = {Concurrent Programs with Simple Data Structures {{\slash}} Sequential Programs with Composite Data Structures}, howpublished = {Deliverable VERIDYC D~2 (ANR-09-SEGI-016)}, month = mar, year = {2012}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/veridyc-d2.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/veridyc-d2.pdf} }

@inproceedings{LV-wsfm11, address = {Clermont-Ferrand, France}, year = 2012, volume = 7176, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Carbone, Marco and Petit, Jean-Marc}, acronym = {{WS-FM}'11}, booktitle = {{R}evised {S}elected {P}apers of the 8th {I}nternational {W}orkshop on {W}eb {S}ervices and {F}ormal {M}ethods ({WS}-{FM}'11)}, author = {Lozes, {\'E}tienne and Villard, Jules}, title = {Reliable Contracts for Unreliable Half-Duplex Communications}, pages = {2-16}, doi = {10.1007/978-3-642-29834-9_2}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/LV-wsfm11.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LV-wsfm11.pdf}, abstract = {Recent trends in formal models of web services description languages and session types focus on the asynchronicity of communications. In this paper, we study a core of these models that arose from our modelling of the Sing\# programming language, and demonstrate correspondences between Sing\# contracts, asynchronous session behaviors, and the subclass of communicating automata with two participants that satisfy the half-duplex property. This correspondence better explains the criteria proposed by Stengel and Bultan for Sing\# contracts to be reliable, and possibly indicate useful criteria for the design of WSDL. We moreover establish a polynomial-time complexity for the analysis of communication contracts under arbitrary models of asynchronicity, and we investigate the model-checking problems against LTL formulas.} }

@inproceedings{LL-fics12, address = {Tallinn, Estonia}, month = mar, year = 2012, volume = 77, series = {Electronic Proceedings in Theoretical Computer Science}, editor = {Miller, Dale and {\'E}sik, Zolt{\'a}n}, acronym = {{FICS}'12}, booktitle = {{P}roceedings of the 8th {W}orkshop on {F}ixed {P}oints in {C}omputer {S}cience ({FICS}'12)}, author = {Lange, Martin and Lozes, {\'E}tienne}, title = {Model-Checking the Higher-Dimensional Modal \(\mu\)-Calculus}, pages = {39-46}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/LL-fics12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LL-fics12.pdf}, doi = {10.4204/EPTCS.77.6}, abstract = {The higher-dimensional modal \(\mu\)-calculus is an extension of the \(\mu\)-calculus in which formulas are interpreted in tuples of states of a labeled transition system. Every property that can be expressed in this logic can be checked in polynomial time, and conversely every polynomial-time decidable problem that has a bisimulation-invariant encoding into labeled transition systems can also be defined in the higher-dimensional modal \(\mu\)-calculus. We exemplify the latter connection by giving several examples of decision problems which reduce to model checking of the higher-dimensional modal \(\mu\)-calculus for some fixed formulas. This way generic model checking algorithms for the logic can then be used via partial evaluation in order to obtain algorithms for theses problems which may benefit from improvements that are well-established in the field of program verification, namely on-the-fly and symbolic techniques. The aim of this work is to extend such techniques to other fields as well, here exemplarily done for process equivalences, automata theory, parsing, string problems, and games.} }

@inproceedings{CD-lics12, address = {Dubrovnik, Croatia}, month = jun, year = 2012, publisher = {{IEEE} Computer Society Press}, acronym = {{LICS}'12}, booktitle = {{P}roceedings of the 27th {A}nnual {IEEE} {S}ymposium on {L}ogic in {C}omputer {S}cience ({LICS}'12)}, author = {Chatterjee, Krishnendu and Doyen, Laurent}, title = {Partial-Observation Stochastic Games: How to Win when Belief Fails}, pages = {175-184}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-lics12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-lics12.pdf}, doi = {10.1109/LICS.2012.28}, abstract = {We consider two-player stochastic games played on finite graphs with reachability objectives where the first player tries to ensure a target state to be visited almost-surely (i.e., with probability~\(1\)), or positively (i.e., with positive probability), no matter the strategy of the second player.\par We classify such games according to the information and the power of randomization available to the players. On the basis of information, the game can be one-sided with either (a)~player~1, or (b)~player~2 having partial observation (and the other player has perfect observation), or two-sided with (c)~both players having partial observation. On the basis of randomization, the players (a)~may not be allowed to use randomization (pure strategies), or (b)~may choose a probability distribution over actions but the actual random choice is external and not visible to the player (actions invisible), or (c)~may use full randomization.\par Our main results for pure strategies are as follows. (1)~For one-sided games with player~1 having partial observation we show that (in contrast to full randomized strategies) belief-based (subset-construction based) strategies are not sufficient, and we present an exponential upper bound on memory both for almost-sure and positive winning strategies; we show that the problem of deciding the existence of almost-sure and positive winning strategies for player~1 is EXPTIME-complete. (2)~For one-sided games with player~2 having partial observation we show that non-elementary memory is both necessary and sufficient for both almost-sure and positive winning strategies. (3)~We~show that for the general (two-sided) case finite-memory strategies are sufficient for both positive and almost-sure winning, and at least non-elementary memory is required.\par We establish the equivalence of the almost-sure winning problems for pure strategies and for randomized strategies with actions invisible. Our equivalence result exhibits serious flaws in previous results of the literature: we show a non-elementary memory lower bound for almost-sure winning whereas an exponential upper bound was previously claimed.} }

@article{CD-tcs12, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Chatterjee, Krishnendu and Doyen, Laurent}, title = {Energy parity games}, volume = 458, year = 2012, month = nov, pages = {49-60}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-tcs12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-tcs12.pdf}, doi = {10.1016/j.tcs.2012.07.038}, abstract = {Energy parity games are infinite two-player turn-based games played on weighted graphs. The objective of the game combines a (qualitative) parity condition with the (quantitative) requirement that the sum of the weights (i.e., the level of energy in the game) must remain positive. Beside their own interest in the design and synthesis of resource-constrained omega-regular specifications, energy parity games provide one of the simplest model of games with combined qualitative and quantitative objectives. Our main results are as follows: (a)~exponential memory is sufficient and may be necessary for winning strategies in energy parity games; (b)~the~problem of deciding the winner in energy parity games can be solved in \(\textsf{NP} \cap \textsf{coNP}\); and (c)~we~give an algorithm to solve energy parity by reduction to energy games. We also show that the problem of deciding the winner in energy parity games is logspace-equivalent to the problem of deciding the winner in mean-payoff parity games, which can thus be solved in \(\textsf{NP} \cap \textsf{coNP}\). As a consequence we also obtain a conceptually simple algorithm to solve mean-payoff parity games.} }

@proceedings{rp2012-FLP, title = {{P}roceedings of the 6th {I}nternational {W}okshop on {R}eachability {P}roblems ({RP}'12)}, booktitle = {{P}roceedings of the 6th {I}nternational {W}okshop on {R}eachability {P}roblems ({RP}'12)}, acronym = {{RP}'12}, editor = {Finkel, Alain and Leroux, J{\'e}r{\^o}me and Potapov, Igor}, publisher = {Springer}, series = {Lecture Notes in Computer Science}, volume = 7550, year = 2012, month = sep, address = {Bordeaux, France}, doi = {10.1007/978-3-642-33512-9}, url = {http://www.springerlink.com/content/978-3-642-33511-2/} }

@inproceedings{FGL-pn12, address = {Hamburg, Germany}, month = jun, year = 2012, volume = 7347, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Haddad, Serge and Pomello, Lucia}, acronym = {{PETRI~NETS}'12}, booktitle = {{P}roceedings of the 33rd {I}nternational {C}onference on {A}pplications and {T}heory of {P}etri {N}ets ({PETRI~NETS}'12)}, author = {Finkel, Alain and Goubault{-}Larrecq, Jean}, title = {The~Theory of~{WSTS}: The~Case of Complete~{WSTS}}, pages = {3-31}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/FGL-atpn12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/FGL-atpn12.pdf}, doi = {10.1007/978-3-642-31131-4_2}, abstract = {We describe a simple, conceptual forward analysis procedure for \(\infty\)-complete WSTS~\(\mathfrak{S}\). This computes the so-called \emph{clover} of a state. When \(\mathfrak{S}\) is the completion of a WSTS~\(\mathfrak{X}\), the clover in~\(\mathfrak{S}\) is a finite description of the downward closure of the reachability set. We show that such completions are \(\infty\)-complete exactly when \(\mathfrak{X}\) is an \emph{\(\omega^{2}\)-WSTS}, a new robust class of WSTS. We show that our procedure terminates in more cases than the generalized Karp-Miller procedure on extensions of Petri nets. We characterize the WSTS where our procedure terminates as those that are \emph{clover-flattable}. Finally, we apply this to well-structured Presburger counter systems.} }

@inproceedings{BFP-fsttcs12, address = {Hyderabad, India}, month = dec, year = 2012, volume = 18, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {D'Souza, Deepak and Radhakrishnan, Jaikumar and Telikepalli, Kavitha}, acronym = {{FSTTCS}'12}, booktitle = {{P}roceedings of the 32nd {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'12)}, author = {Bonnet, R{\'e}mi and Finkel, Alain and Praveen, M.}, title = {Extending the {R}ackoff technique to affine nets}, nopages = {}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BFP-fsttcs12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BFP-fsttcs12.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2012.301}, abstract = {We study the possibility of extending the Rackoff technique to Affine nets, which are Petri nets extended with affine functions. The Rackoff technique has been used for establishing \textsc{Expspace} upper bounds for the coverability and boundedness problems for Petri nets. We show that this technique can be extended to strongly increasing Affine nets, obtaining better upper bounds compared to known results. The possible copies between places of a strongly increasing Affine net make this extension non-trivial. One cannot expect similar results for the entire class of Affine nets since coverability is Ackermann-hard and boundedness is undecidable. Moreover, it can be proved that model checking a logic expressing generalized coverability properties is undecidable for strongly increasing Affine nets, while it is known to be \textsc{Expspace}-complete for Petri nets.} }

@article{BS-fmsd2012, publisher = {Springer}, journal = {Formal Methods in System Design}, author = {Bertrand, Nathalie and Schnoebelen, {\relax Ph}ilippe}, title = {Computable fixpoints in well-structured symbolic model checking}, pages = {233-267}, volume = 43, number = 2, month = oct, year = 2013, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BS-fmsd12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BS-fmsd12.pdf}, doi = {10.1007/s10703-012-0168-y}, abstract = {We prove a general finite-time convergence theorem for fixpoint expressions over a well-quasi-ordered set. This has immediate applications for the verification of well-structured systems, where a main issue is the computability of fixpoint expressions, and in particular for game-theoretical properties and probabilistic systems where nesting and alternation of least and greatest fixpoints are common.} }

@inproceedings{jks-ifiptcs12, address = {Amsterdam, The Netherlands}, month = sep, year = 2012, volume = {7604}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Baeten, Jos and Ball, Tom and de~Boer, Frank}, acronym = {{IFIP~TCS}'12}, booktitle = {{P}roceedings of the 7th {IFIP} {I}nternational {C}onference on {T}heoretical {C}omputer {S}cience ({IFIP~TCS}'12)}, author = {Jan\v{c}ar, Petr and Karandikar, Prateek and Schnoebelen, {\relax Ph}ilippe}, title = {Unidirectional channel systems can be tested}, pages = {149-163}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/JKS-ifiptcs12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/JKS-ifiptcs12.pdf}, doi = {10.1007/978-3-642-33475-7_11}, abstract = {{"}Unidirectional channel systems{"} (Chambart~\& Schnoebelen, CONCUR~2008) are systems where one-way communication from a sender to a receiver goes via one reliable and one unreliable (unbounded fifo) channel. Equipping these systems with the possibility of testing regular properties on the contents of channels makes verification undecidable. Decidability is preserved when only emptiness and nonemptiness tests are considered: the proof relies on a series of reductions eventually allowing us to take advantage of recent results on Post's Embedding Problem.} }

@article{BFLZ-lmcs12, journal = {Logical Methods in Computer Science}, author = {Bonnet, R{\'e}mi and Finkel, Alain and Leroux, J{\'e}r{\^o}me and Zeitoun, Marc}, title = {Model Checking Vector Addition Systems with one zero-test}, year = 2012, volume = {8}, number = {2:11}, nopages = {}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BFLZ-lmcs12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BFLZ-lmcs12.pdf}, doi = {10.2168/LMCS-8(2:11)2012}, abstract = {We design a variation of the Karp-Miller algorithm to compute, in a forward manner, a finite representation of the cover (i.e., the downward closure of the reachability set) of a vector addition system with one zero-test. This algorithm yields decision procedures for several problems for these systems, open until now, such as place-boundedness or LTL model-checking. The proof techniques to handle the zero-test are based on two new notions of cover: the refined and the filtered cover. The refined cover is a hybrid between the reachability set and the classical cover. It inherits properties of the reachability set: equality of two refined covers is undecidable, even for usual Vector Addition Systems (with no zero-test), but the refined cover of a Vector Addition System is a recursive set. The second notion of cover, called the filtered cover, is the central tool of our algorithms. It inherits properties of the classical cover, and in particular, one can effectively compute a finite representation of this set, even for Vector Addition Systems with one zero-test.} }

@phdthesis{lozes-HDR12, author = {Lozes, {\'E}tienne}, title = {Separation Logic: Expressiveness and Copyless Message-Passing}, year = 2012, month = jul, type = {M{\'e}moire d'habilitation}, school = {{\'E}cole Normale Sup{\'e}rieure de Cachan, France}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/hdr-el12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/hdr-el12.pdf} }

@inproceedings{CD-aiml12, address = {Copenhagen, Denmark}, month = aug, year = 2012, publisher = {College Publications}, editor = {Bolander, Thomas and Bra{\"u}ner, Torben and Ghilardi, Silvio and Moss, Lawrence}, acronym = {{AiML}'12}, booktitle = {{S}elected {P}apers from the 9th {W}orkshop on {A}dvances in {M}odal {L}ogics ({AiML}'12)}, author = {Carreiro, Facundo and Demri, St{\'e}phane}, title = {Beyond Regularity for {P}resburger Modal Logics}, pages = {161-182}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-aiml12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CD-aiml12.pdf}, abstract = {Satisfiability problem for modal logic~K with quantifier-free Presburger and regularity constraints~(EML) is known to be pspace-complete. In this paper, we consider its extension with nonregular constraints, and more specifically those expressed by visibly pushdown languages~(VPL). This class of languages behaves nicely, in particular when combined with Propositional Dynamic Logic~(PDL). By extending EML, we show that decidability is preserved if we allow at most one positive VPL-constraint at each modal depth. However, the presence of two VPL-contraints or the presence of a negative occurrence of a single VPL-constraint leads to undecidability. These results contrast with the decidability of PDL augmented with VPL-constraints.} }

@inproceedings{HSS-lics2012, address = {Dubrovnik, Croatia}, month = jun, year = 2012, publisher = {{IEEE} Computer Society Press}, acronym = {{LICS}'12}, booktitle = {{P}roceedings of the 27th {A}nnual {IEEE} {S}ymposium on {L}ogic in {C}omputer {S}cience ({LICS}'12)}, author = {Haddad, Serge and Schmitz, Sylvain and Schnoebelen, {\relax Ph}ilippe}, title = {The Ordinal-Recursive Complexity of Timed-Arc {P}etri Nets, Data Nets, and Other Enriched Nets}, pages = {355-364}, url = {http://hal.archives-ouvertes.fr/hal-00793811}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HSS-lics12.pdf}, doi = {10.1109/LICS.2012.46}, abstract = {We show how to reliably compute fast-growing functions with timed-arc Petri nets and data nets. This construction provides ordinal-recursive lower bounds on the complexity of the main decidable properties (safety, termination, regular simulation,~etc.) of these models. Since these new lower bounds match the upper bounds that one can derive from wqo theory, they precisely characterise the computational power of these so-called {"}enriched{"} nets.} }

@inproceedings{DDS-ijcar12, address = {Manchester, UK}, month = jun, year = 2012, volume = {7364}, series = {Lecture Notes in Artificial Intelligence}, publisher = {Springer-Verlag}, editor = {Gramlich, Bernhard and Miller, Dale and Sattler, Uli}, acronym = {{IJCAR}'12}, booktitle = {{P}roceedings of the 6th {I}nternational {J}oint {C}onference on {A}utomated {R}easoning ({IJCAR}'12)}, author = {Demri, St{\'e}phane and Dhar, Amit Kumar and Sangnier, Arnaud}, title = {Taming Past {LTL} and Flat Counter Systems}, pages = {179-193}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DDS-ijcar12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DDS-ijcar12.pdf}, doi = {10.1007/978-3-642-31365-3_16}, abstract = {Reachability and LTL model-checking problems for flat counter systems are known to be decidable but whereas the reachability problem can be shown in NP, the best known complexity upper bound for the latter problem is made of a tower of several exponentials. Herein, we show that the problem is only NP-complete even if LTL admits past-time operators and arithmetical constraints on counters. Actually, the NP upper bound is shown by adequately combining a new stuttering theorem for Past LTL and the property of small integer solutions for quantifier-free Presburger formulae. Other complexity results are proved, for instance for restricted classes of flat counter systems.} }

@article{BMOSW-fac12, publisher = {Springer}, journal = {Formal Aspects of Computing}, author = {Bouyer, Patricia and Markey, Nicolas and Ouaknine, Jo{\"e}l and Schnoebelen, {\relax Ph}ilippe and Worrell, James}, title = {On Termination and Invariance for Faulty Channel Systems}, year = 2012, month = jul, volume = 24, number = {4-6}, pages = {595-607}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BMOSU-fac12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BMOSU-fac12.pdf}, doi = {10.1007/s00165-012-0234-7}, abstract = {A~\emph{channel machine} consists of a finite controller together with several fifo channels; the controller can read messages from the head of a channel and write messages to the tail of a channel. In this paper we focus on channel machines with \emph{insertion errors}, i.e., machines in whose channels messages can spontaneously appear. We consider the invariance problem: does a given insertion channel machine have an infinite computation all of whose configurations satisfy a given predicate? We show that this problem is primitive-recursive if the predicate is closed under message losses. We also give a non-elementary lower bound for the invariance problem under this restriction. Finally, using the previous result, we show that the satisfiability problem for the safety fragment of Metric Temporal Logic is non-elementary.} }

@article{jcss12-DJLL, publisher = {Elsevier Science Publishers}, journal = {Journal of Computer and System Sciences}, author = {Demri, St{\'e}phane and Jurdzi{\'n}ski, Marcin and Lachish, Oded and Lazi{\'c}, Ranko}, title = {The covering and boundedness problems for branching vector addition systems}, year = {2012}, volume = 79, number = 1, pages = {23-38}, month = feb, url = {http://www.lsv.fr/Publis/PAPERS/PDF/djll-jcss12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/djll-jcss12.pdf}, doi = {10.1016/j.jcss.2012.04.002}, abstract = {The covering and boundedness problems for branching vector addition systems are shown complete for doubly-exponential time.} }

@inproceedings{KS-csr12, address = {Nizhni Novgorod, Russia}, month = jul, year = 2012, volume = {7353}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Hirsch, Edward A. and Karhum{\"a}ki, Juhani and Lepist{\"o}, Arto and Prilutskii, Michail}, acronym = {{CSR}'12}, booktitle = {{P}roceedings of the 7th {I}nternational {C}omputer {S}cience {S}ymposium in {R}ussia ({CSR}'12)}, author = {Karandikar, Prateek and Schnoebelen, {\relax Ph}ilippe}, title = {Cutting Through Regular {P}ost Embedding Problems}, pages = {229-240}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-csr12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-csr12.pdf}, doi = {10.1007/978-3-642-30642-6_22}, abstract = {The Regular Post Embedding Problem extended with partial (co)directness is shown decidable. This extends to universal and{\slash}or counting versions. It is also shown that combining directness and codirectness in Post Embedding problems leads to undecidability.} }

@phdthesis{doyen-HDR11, author = {Doyen, Laurent}, title = {Games and Automata: From Boolean to Quantitative Verification}, year = 2012, month = mar, type = {M{\'e}moire d'habilitation}, school = {{\'E}cole Normale Sup{\'e}rieure de Cachan, France}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/hdr-ld.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/hdr-ld.pdf}, noslides = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/SLIDES/hdr-ld-slides.pdf} }

@article{BDL-icomp12, publisher = {Elsevier Science Publishers}, journal = {Information and Computation}, author = {Brochenin, R{\'e}mi and Demri, St{\'e}phane and Lozes, {\'E}tienne}, title = {On the Almighty Wand}, year = {2012}, volume = 211, pages = {106-137}, month = feb, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BDL-icomp12.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BDL-icomp12.pdf}, doi = {10.1016/j.ic.2011.12.003}, abstract = {We investigate decidability, complexity and expressive power issues for (first-order) separation logic with one record field (herein called~\texttt{SL}) and its fragments. \texttt{SL}~can specify properties about the memory heap of programs with singly-linked lists. Separation logic with two record fields is known to be undecidable by reduction of finite satisfiability for classical predicate logic with one binary relation. Surprisingly, we show that second-order logic is as expressive as \texttt{SL} and as a by-product we get undecidability of~\texttt{SL}. This is refined by showing that \texttt{SL} without the separating conjunction is as expressive as~\texttt{SL}, whence undecidable too. As a consequence, in \texttt{SL} the separating implication (also known as the magic wand) can simulate the separating conjunction. By~contrast, we establish that \texttt{SL} without the magic wand is decidable, and we~prove a non-elementary complexity by reduction from satisfiability for the first-order theory over finite words. This result is extended with a bounded use of the magic wand that appears in Hoare-style rules. As a generalisation, it~is shown that~\(k\texttt{SL}\), the separation logic over heaps with \(k\geq 1\) record fields, is equivalent to~\(k\texttt{SO}\), the second-order logic over heaps with \(k\) record fields.} }

@inproceedings{BD-csr13, address = {Ekaterinburg, Russia}, month = jun, year = 2013, volume = {7913}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Bulatov, Andrei A. and Shur, Arseny M.}, acronym = {{CSR}'13}, booktitle = {{P}roceedings of the 8th {I}nternational {C}omputer {S}cience {S}ymposium in {R}ussia ({CSR}'13)}, author = {Bansal, Kshitij and Demri, St{\'e}phane}, title = {Model-checking bounded multi-pushdown systems}, pages = {405-417}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BD-csr13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BD-csr13.pdf}, doi = {10.1007/978-3-642-38536-0_35}, abstract = {We provide complexity characterizations of model checking multi-pushdown systems. We consider three standard notions for boundedness: context boundedness, phase boundedness and stack ordering. The logical formalism is a linear-time temporal logic extending well-known logic \texttt{CaRet} but dedicated to multi-pushdown systems in which abstract operators are parameterized by stacks. We show that the problem is ExpTime-complete for context-bounded runs and unary encoding of the number of context switches; we also prove that the problem is 2ExpTime-complete for phase-bounded runs and unary encoding of the number of phase switches. In both cases, the value~\(k\) is given as an input, which makes a substantial difference in the complexity.} }

@inproceedings{BC-fossacs13, address = {Rome, Italy}, month = mar, year = 2013, volume = {7794}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Pfenning, Frank}, acronym = {{FoSSaCS}'13}, booktitle = {{P}roceedings of the 16th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'13)}, author = {Bonnet, R{\'e}mi and Chadha, Rohit}, title = {Bounded Context-Switching and Reentrant Locking}, pages = {65-80}, doi = {10.1007/978-3-642-37075-5_5}, abstract = {Reentrant locking is a \emph{recursive locking} mechanism which allows a thread in a multi-threaded program to acquire the reentrant lock multiple times. The thread must release this lock an equal number of times before another thread can acquire this lock. We consider the control state reachability problem for recursive multi-threaded programs synchronizing via a finite number of reentrant locks. Such programs can be abstracted as multi-pushdown systems with a finite number of counters. The pushdown stacks model the call stacks of the threads and the counters model the reentrant locks. The control state reachability problem is already undecidable for non-reentrant locks. As a consequence, for non-reentrant locks, under-approximation techniques which restrict the search space have gained traction. One popular technique is to limit the number of context switches. Our main result is that the problem of checking whether a control state is reachable within a bounded number of context switches is decidable for recursive multi-threaded programs synchronizing via a finite number of reentrant locks if we restrict the lock-usage to contextual locking: a release of an instance of reentrant lock can only occur if the instance was acquired before in the same procedure and each instance of a reentrant lock acquired in a procedure call must be released before the procedure returns. The decidability is obtained by a reduction to the reachability problem of Vector Addition Systems with States~(VASS).} }

@article{BCMV-lmcs13, journal = {Logical Methods in Computer Science}, author = {Bonnet, R{\'e}mi and Chadha, Rohit and Madhusudan, P. and Viswanathan, Mahesh}, title = {Reachability under contextual locking}, volume = 9, number = {3:21}, month = sep, year = 2013, nopages = {}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BCMV-lmcs13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BCMV-lmcs13.pdf}, doi = {10.2168/LMCS-9(3:21)2013}, abstract = {The pairwise reachability problem for a multi-threaded program asks, given control locations in two threads, whether they can be simultaneously reached in an execution of the program. The problem is important for static analysis and is used to detect statements that are concurrently enabled. This problem is in general undecidable even when data is abstracted and when the threads (with recursion) synchronize only using a finite set of locks. Popular programming paradigms that limit the lock usage patterns have been identified under which the pairwise reachability problem becomes decidable. In this paper, we consider a new natural programming paradigm, called contextual locking, which ties the lock usage to calling patterns in each thread: we assume that locks are released in the same context that they were acquired and that every lock acquired by a thread in a procedure call is released before the procedure returns. Our main result is that the pairwise reachability problem is polynomial-time decidable for this new programming paradigm as well. The problem becomes undecidable if the locks are reentrant; reentrant locking is a recursive locking mechanism which allows a thread in a multi-threaded program to acquire the reentrant lock multiple times.} }

@phdthesis{brochenin-phd2013, author = {Brochenin, R{\'e}mi}, title = {Separation Logic: Expressiveness, Complexity, Temporal Extension}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, type = {Th{\`e}se de doctorat}, year = 2013, month = sep, url = {http://www.lsv.fr/Publis/PAPERS/PDF/brochenin-phd13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/brochenin-phd13.pdf} }

@inproceedings{reichert-rp13, address = {Uppsala, Sweden}, month = sep, year = 2013, volume = {8169}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Abdulla, Parosh Aziz and Potapov, Igor}, acronym = {{RP}'13}, booktitle = {{P}roceedings of the 7th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'13)}, author = {Reichert, Julien}, title = {On The Complexity of Counter Reachability Games}, pages = {196-208}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/JR-rp13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/JR-rp13.pdf}, doi = {10.1007/978-3-642-41036-9_18}, abstract = {Counter reachability games are played by two players on a graph with labelled edges. Each move consists in picking an edge from the current location and adding its label to a counter vector. The objective is to reach a given counter value in a given location. We distinguish three semantics for counter reachability games, according to what happens when a counter value would become negative: the edge is either disabled, or enabled but the counter value becomes zero, or enabled. We consider the problem of deciding the winner in counter reachability games and show that, in most cases, it has the same complexity under all semantics. Surprisingly, under one semantics, the complexity in dimension one depends on whether the objective value is zero or any other integer.} }

@inproceedings{DDS-icalp13, address = {Riga, Latvia}, month = jul, year = 2013, volume = {7966}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Fomin, Fedor V. and Freivalds, R{\=u}si{\c{n}}{\v{s}} and Kwiatkowska, Marta and Peleg, David}, acronym = {{ICALP}'13}, booktitle = {{P}roceedings of the 40th {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'13)~-- {P}art~{II}}, author = {Demri, St{\'e}phane and Dhar, Amit Kumar and Sangnier, Arnaud}, title = {On the Complexity of Verifying Regular Properties on Flat Counter Systems}, pages = {162-173}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DDS-icalp13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DDS-icalp13.pdf}, doi = {10.1007/978-3-642-39212-2_17}, abstract = {Among the approximation methods for the verification of counter systems, one of them consists in model-checking their flat unfoldings. Unfortunately, the complexity characterization of model-checking problems for such operational models is not always well studied except for reachability queries or for Past LTL. In this paper, we characterize the complexity of model-checking problems on flat counter systems for the specification languages including first-order logic, linear mu-calculus, infinite automata, and related formalisms. Our results span different complexity classes (mainly from PTime to PSpace) and they apply to languages in which arithmetical constraints on counter values are systematically allowed. As far as the proof techniques are concerned, we provide a uniform approach that focuses on the main issues.} }

@inproceedings{GHPR-pn13, address = {Milano, Italy}, month = jun, year = 2013, volume = {7927}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Colom, Jos{\'e}-Manuel and Desel, J{\"o}rg}, acronym = {{PETRI~NETS}'13}, booktitle = {{P}roceedings of the 34th {I}nternational {C}onference on {A}pplications and {T}heory of {P}etri {N}ets ({PETRI~NETS}'13)}, author = {Geeraerts, Gilles and Heu{\ss}ner, Alexander and Praveen, M. and Raskin, Jean-Fran{\c{c}}ois}, title = {{{\(\omega\)}}-{P}etri nets}, pages = {49-69}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/GHPR-atpn13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/GHPR-atpn13.pdf}, doi = {10.1007/978-3-642-38697-8_4}, abstract = {We introduce \(\omega\)-Petri nets (\(\omega\)PN), an extension of plain Petri nets with \(\omega\)-labeled input and output arcs, that is well-suited to analyse parametric concurrent systems with dynamic thread creation. Most techniques (such as the Karp and Miller tree or the Rackoff technique) that have been proposed in the setting of plain Petri nets do not apply directly to \(\omega\)PN because \(\omega\)PN define transition systems that have infinite branching. This motivates a thorough analysis of the computational aspects of~\(\omega\)PN. We show that an \(\omega\)PN can be turned into a plain Petri net that allows to recover the reachability set of the \(\omega\)PN, but that does not preserve termination. This yields complexity bounds for the reachability, (place) boundedness and coverability problems on \(\omega\)PN. We provide a practical algorithm to compute a coverability set of the \(\omega\)PN and to decide termination by adapting the classical Karp and Miller tree construction. We also adapt the Rackoff technique to \(\omega\)PN, to obtain the exact complexity of the termination problem. Finally, we consider the extension of \(\omega\)PN with reset and transfer arcs, and show how this extension impacts the decidability and complexity of the aforementioned problems.} }

@inproceedings{BDGORW-atva13, address = {Hanoi, Vietnam}, month = oct, year = {2013}, volume = {8172}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Dang{-}Van, Hung and Ogawa, Mizuhito}, acronym = {{ATVA}'13}, booktitle = {{P}roceedings of the 11th {I}nternational {S}ymposium on {A}utomated {T}echnology for {V}erification and {A}nalysis ({ATVA}'13)}, author = {Brihaye, {\relax Th}omas and Doyen, Laurent and Geeraerts, Gilles and Ouaknine, Jo{\"e}l and Raskin, Jean-Fran{\c{c}}ois and Worrell, James}, title = {Time-Bounded Reachability for Monotonic Hybrid Automata: Complexity and Fixed Points}, pages = {55-70}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BDGORW-atva13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BDGORW-atva13.pdf}, doi = {10.1007/978-3-319-02444-8_6}, abstract = {We study the \emph{time-bounded reachability problem} for \emph{monotonic hybrid automata} (MHA), i.e., rectangular hybrid automata for which the rate of each variable is either always non-negative or always non-positive. In this paper, we revisit the decidability results presented in [Brihaye et~al., \textit{On reachability for hybrid automata over bounded time}, ICALP~2011] and show that the problem is NExpTime-complete. We also show that we can effectively compute fixed points that characterise the sets of states that are reachable (resp. co-reachable) within \(T\) time units from a given state.} }

@inproceedings{CDRR-atva13, address = {Hanoi, Vietnam}, month = oct, year = {2013}, volume = {8172}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Dang{-}Van, Hung and Ogawa, Mizuhito}, acronym = {{ATVA}'13}, booktitle = {{P}roceedings of the 11th {I}nternational {S}ymposium on {A}utomated {T}echnology for {V}erification and {A}nalysis ({ATVA}'13)}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Randour, Mickael and Raskin, Jean-Fran{\c{c}}ois}, title = {Looking at Mean-Payoff and Total-Payoff through Windows}, pages = {118-132}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDRR-atva13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDRR-atva13.pdf}, doi = {10.1007/978-3-319-02444-8_10}, abstract = {We consider two-player games played on weighted directed graphs with mean-payoff and total-payoff objectives, two classical quantitative objectives. While for single-dimensional games the complexity and memory bounds for both objectives coincide, we show that in contrast to multi-dimensional mean-payoff games that are known to be coNP-complete, multi-dimensional total-payoff games are undecidable. We introduce conservative approximations of these objectives, where the payoff is considered over a local finite window sliding along a play, instead of the whole play. For single dimension, we show that (i)~if the window size is polynomial, deciding the winner takes polynomial time, and (ii)~the existence of a bounded window can be decided in NP coNP, and is at least as hard as solving mean-payoff games. For multiple dimensions, we show that (i)~the problem with fixed window size is EXPTIME-complete, and (ii)~there is no primitive-recursive algorithm to decide the existence of a bounded window.} }

@inproceedings{SS-concur13, address = {Buenos Aires, Argentina}, month = aug, year = 2013, volume = 8052, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {D'Argenio, Pedro R. and Melgratti, Hern{\'a}n)}, acronym = {{CONCUR}'13}, booktitle = {{P}roceedings of the 24th {I}nternational {C}onference on {C}oncurrency {T}heory ({CONCUR}'13)}, author = {Schmitz, Sylvain and Schnoebelen, {\relax Ph}ilippe}, title = {The Power of Well-Structured Systems}, pages = {5-24}, url = {http://arxiv.org/abs/1402.2908}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/SS-concur13.pdf}, doi = {10.1007/978-3-642-40184-8_2}, abstract = {Well-structured systems, aka WSTS, are computational models where the set of possible configurations is equipped with a well-quasi-ordering which is compatible with the transition relation between configurations. This structure supports generic decidability results that are important in verification and several other fields. This paper recalls the basic theory underlying well-structured systems and shows how two classic decision algorithms can be formulated as an exhaustive search for some {"}bad{"} sequences. This lets us describe new powerful techniques for the complexity analysis of WSTS algorithms. Recently, these techniques have been successful in precisely characterizing the power, in a complexity-theoretical sense, of several important WSTS models like unreliable channel systems, monotonic counter machines, or networks of timed systems.} }

@inproceedings{HSS-concur13, address = {Buenos Aires, Argentina}, month = aug, year = 2013, volume = 8052, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {D'Argenio, Pedro R. and Melgratti, Hern{\'a}n)}, acronym = {{CONCUR}'13}, booktitle = {{P}roceedings of the 24th {I}nternational {C}onference on {C}oncurrency {T}heory ({CONCUR}'13)}, author = {Haase, Christoph and Schmitz, Sylvain and Schnoebelen, {\relax Ph}ilippe}, title = {The Power of Priority Channel Systems}, pages = {319-333}, url = {http://arxiv.org/abs/1301.5500}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HSS-corr13.pdf}, arxivpdf = {http://arxiv.org/pdf/1301.5500}, doi = {10.1007/978-3-642-40184-8_23}, abstract = {We introduce Priority Channel Systems, a new natural class of channel systems where messages carry a numeric priority and where higher-priority messages can supersede lower-priority messages preceding them in the fifo communication buffers. The decidability of safety and inevitability properties is shown via the introduction of a \emph{priority embedding}, a~well-quasi-ordering that has not previously been used in well-structured systems. We then show how Priority Channel Systems can compute Fast-Growing functions and prove that the aforementioned verification problems are \(F_{\epsilon_{0}}\)-complete.} }

@inproceedings{FGH-mfcs13, address = {Klosterneuburg, Austria}, month = aug, year = 2013, volume = {8087}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Chatterjee, Krishnendu and Sgall, Ji{\v{r}}{\'\i}}, acronym = {{MFCS}'13}, booktitle = {{P}roceedings of the 38th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'13)}, author = {Finkel, Alain and G{\"o}ller, Stefan and Haase, Christoph}, title = {Reachability in Register Machines with Polynomial Updates}, pages = {409-420}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/FGH-mfcs13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/FGH-mfcs13.pdf}, ps = {FGH-mfcs13.ps}, doi = {10.1007/978-3-642-40313-2_37}, abstract = {This paper introduces a class of register machines whose registers can be updated by polynomial functions when a transition is taken, and the domain of the registers can be constrained by linear constraints. This model strictly generalises a variety of known formalisms such as various classes of Vector Addition Systems with States. Our main result is that reachability in our class is PSPACE-complete when restricted to one register. We moreover give a classification of the complexity of reachability according to the type of polynomials allowed and the geometry induced by the range-constraining formula.} }

@inproceedings{McK-dcfs13, address = {London, Ontario, Canada}, month = jul, year = 2013, volume = {8031}, series = {Lecture Notes in Computer Science}, publisher = {Springer-Verlag}, acronym = {{DCFS}'13}, booktitle = {{P}roceedings of the 15th {W}orkshop on {D}escriptional {C}omplexity of {F}ormal {S}ystems ({DCFS}'13)}, author = {McKenzie, Pierre}, title = {Can chimps go it alone?}, pages = {17}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/McK-dcfs13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/McK-dcfs13.pdf}, doi = {10.1007/978-3-642-39310-5_3} }

@inproceedings{DFP-lics13, address = {New-Orleans, Louisiana, USA}, month = jun, year = 2013, publisher = {{IEEE} Computer Society Press}, acronym = {{LICS}'13}, booktitle = {{P}roceedings of the 28th {A}nnual {IEEE} {S}ymposium on {L}ogic in {C}omputer {S}cience ({LICS}'13)}, author = {Demri, St{\'e}phane and Figueira, Diego and Praveen, M.}, title = {Reasoning about Data Repetitions with Counter Systems}, pages = {33-42}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DFP-lics13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DFP-lics13.pdf}, doi = {10.1109/LICS.2013.8}, abstract = {We study linear-time temporal logics interpreted over data words with multiple attributes. We restrict the atomic formulas to equalities of attribute values in successive positions and to repetitions of attribute values in the future or past. We demonstrate correspondences between satisfiability problems for logics and reachability-like decision problems for counter systems. We show that allowing/disallowing atomic formulas expressing repetitions of values in the past corresponds to the reachability\slash coverability problem in Petri nets. This gives us 2EXPSPACE upper bounds for several satisfiability problems. We prove matching lower bounds by reduction from a reachability problem for a newly introduced class of counter systems. This new class is a succinct version of vector addition systems with states in which counters are accessed via pointers, a potentially useful feature in other contexts. We strengthen further the correspondences between data logics and counter systems by characterizing the complexity of fragments, extensions and variants of the logic. For instance, we precisely characterize the relationship between the number of attributes allowed in the logic and the number of counters needed in the counter system.} }

@inproceedings{BS-lics13, address = {New-Orleans, Louisiana, USA}, month = jun, year = 2013, publisher = {{IEEE} Computer Society Press}, acronym = {{LICS}'13}, booktitle = {{P}roceedings of the 28th {A}nnual {IEEE} {S}ymposium on {L}ogic in {C}omputer {S}cience ({LICS}'13)}, author = {Boral, Anudhyan and Schmitz, Sylvain}, title = {Model Checking Parse Trees}, pages = {153-162}, url = {http://arxiv.org/abs/1211.5256}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BS-lics13.pdf}, arxivpdf = {http://arxiv.org/pdf/1211.5256}, doi = {10.1109/LICS.2013.21}, abstract = {Parse trees are fundamental syntactic structures in both computational linguistics and compilers construction. We argue in this paper that, in both fields, there are good incentives for model-checking sets of parse trees for some word according to a context-free grammar. We put forward the adequacy of propositional dynamic logic (PDL) on trees in these applications, and study as a sanity check the complexity of the corresponding model-checking problem: although complete for exponential time in the general case, we find natural restrictions on grammars for our applications and establish complexities ranging from nondeterministic polynomial time to polynomial space in the relevant cases.} }

@inproceedings{HIOP-cav13, address = {Saint Petersburg, Russia}, month = jul, year = 2013, volume = {8044}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Sharygina, Natasha and Veith, Helmut}, acronym = {{CAV}'13}, booktitle = {{P}roceedings of the 25th {I}nternational {C}onference on {C}omputer {A}ided {V}erification ({CAV}'13)}, author = {Haase, Christoph and Ishtiaq, Samin and Ouaknine, Jo{\"e}l and Parkinson, Matthew}, title = {SeLoger: A~Tool for Graph-Based Reasoning in Separation Logic}, pages = {790-795}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/HIOP-cav13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HIOP-cav13.pdf}, doi = {10.1007/978-3-642-39799-8_55}, abstract = {This paper introduces the tool SeLoger, which is a reasoner for satisfiability and entailment in a fragment of separation logic with pointers and linked lists. SeLoger builds upon and extends graph-based algorithms that have recently been introduced in order to settle both decision problems in polynomial time. Running SeLoger on standard benchmarks shows that the tool outperforms current state-of-the-art tools by orders of magnitude.} }

@inproceedings{AR-qapl2013, address = {Rome, Italy}, volume = {117}, series = {Electronic Proceedings in Theoretical Computer Science}, month = jun, year = 2013, editor = {Bortolussi, Luca and Wiklicky, Herbert}, acronym = {{QAPL}'13}, booktitle = {{P}roceedings of the 11th {I}nternational {W}orkshop on {Q}uantitative {A}spects of {P}rogramming {L}anguages ({QAPl}'13)}, author = {Arul, Arjun and Reichert, Julien}, title = {The Complexity of Robot Games on the Integer Line}, pages = {132-148}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/AR-qapl13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/AR-qapl13.pdf}, doi = {10.4204/EPTCS.117.9}, abstract = {In robot games on~\(\mathbb{Z}\), two players add integers to a counter. Each player has a finite set from which he picks the integer to add, and the objective of the first player is to let the counter reach~\(0\). We present an exponential-time algorithm for deciding the winner of a robot game given the initial counter value, and prove a matching lower bound.} }

@inproceedings{BS-qapl2013, address = {Rome, Italy}, volume = {117}, series = {Electronic Proceedings in Theoretical Computer Science}, month = jun, year = 2013, editor = {Bortolussi, Luca and Wiklicky, Herbert}, acronym = {{QAPL}'13}, booktitle = {{P}roceedings of the 11th {I}nternational {W}orkshop on {Q}uantitative {A}spects of {P}rogramming {L}anguages ({QAPl}'13)}, author = {Bertrand, Nathalie and Schnoebelen, {\relax Ph}ilippe}, title = {Solving stochastic B{\"u}chi games on infinite arenas with a finite attractor}, pages = {116-131}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BS-qapl2013.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BS-qapl2013.pdf}, doi = {10.4204/EPTCS.117.8}, abstract = {We consider games played on an infinite probabilistic arena where the first player aims at satisfying generalized B{\"u}chi objectives almost surely, i.e., with probability one. We provide a fixpoint characterization of the winning sets and associated winning strategies in the case where the arena satisfies the finite-attractor property. From this we directly deduce the decidability of these games on probabilistic lossy channel systems.} }

@article{CDH-fmsd13, publisher = {Springer}, journal = {Formal Methods in System Design}, author = {Chatterjee, Krishnendu and Doyen, Laurent and Henzinger, {\relax Th}omas A.}, title = {A~survey of partial-observation stochastic parity games}, volume = 43, number = 2, pages = {268-284}, month = oct, year = 2013, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CDH-fmsd13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CDH-fmsd13.pdf}, doi = {10.1007/s10703-012-0164-2}, abstract = {We consider two-player zero-sum stochastic games on graphs with \(\omega\)-regular winning conditions specified as parity objectives. These games have applications in the design and control of reactive systems. We survey the complexity results for the problem of deciding the winner in such games, and in classes of interest obtained as special cases, based on the information and the power of randomization available to the players, on the class of objectives and on the winning mode.\par On the basis of information, these games can be classified as follows: (a)~partial-observation (both players have partial view of the game); (b)~one-sided partial-observation (one player has partial-observation and the other player has complete-observation); and (c)~complete-observation (both players have complete view of the game). The one-sided partial-observation games have two important subclasses: the one-player games, known as partial-observation Markov decision processes~(POMDPs), and the blind one-player games, known as probabilistic automata.\par On the basis of randomization, (a)~the players may not be allowed to use randomization (pure strategies), or (b)~they may choose a probability distribution over actions but the actual random choice is external and not visible to the player (actions invisible), or (c)~they may use full randomization.\par Finally, various classes of games are obtained by restricting the parity objective to a reachability, safety, B{\"u}chi, or coB{\"u}chi condition. We also consider several winning modes, such as sure-winning (i.e., all outcomes of a strategy have to satisfy the winning condition), almost-sure winning (i.e., winning with probability~\(1\)), limit-sure winning (i.e., winning with probability arbitrarily close to~\(1\)), and value-threshold winning (i.e., winning with probability at least~\(v\), where \(v\) is a given rational).} }

@article{demri-jcss13, publisher = {Elsevier Science Publishers}, journal = {Journal of Computer and System Sciences}, author = {Demri, St{\'e}phane}, title = {On selective unboundedness of~{VASS}}, year = {2013}, volume = {79}, number = {5}, pages = {689-713}, month = aug, url = {http://www.lsv.fr/Publis/PAPERS/PDF/demri-jcss13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/demri-jcss13.pdf}, doi = {10.1016/j.jcss.2013.01.014}, abstract = {Numerous properties of vector addition systems with states amount to checking the (un)boundedness of some selective feature (e.g., number of reversals, counter values, run lengths). Some of these features can be checked in exponential space by using Rackoff's proof or its variants, combined with Savitch's Theorem. However, the question is still open for many others, e.g., regularity detection problem and reversal-boundedness detection problem. In the paper, we introduce the class of generalized unboundedness properties that can be verified in exponential space by extending Rackoff's technique, sometimes in an unorthodox way. We obtain new optimal upper bounds, for example for place boundedness problem, reversal-boundedness detection (several variants are present in the paper), strong promptness detection problem and regularity detection. Our analysis is sufficiently refined so as to obtain a polynomial-space bound when the dimension is fixed.} }

@phdthesis{bonnet-phd2013, author = {Bonnet, R{\'e}mi}, title = {Theory of Well-Structured Transition Systems and Extended Vector-Addition Systems}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, type = {Th{\`e}se de doctorat}, year = 2013, month = jan, url = {http://www.lsv.fr/Publis/PAPERS/PDF/bonnet-phd13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/bonnet-phd13.pdf} }

@techreport{rr-lsv-13-02, author = {Doyen, Laurent and Rabinovich, Alexander}, title = {Robot games}, institution = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France}, year = {2013}, month = jan, type = {Research Report}, number = {LSV-13-02}, url = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2013-02.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/RAPPORTS_LSV/PDF/rr-lsv-2013-02.pdf}, versions = {http://www.lsv.fr/Publis/PAPERS/PDF/rr-lsv-2013-02-v1.pdf, 20130124}, note = {2~pages}, abstract = {We introduce robot games, and we give the simplest definition for which decidability is open.} }

@inproceedings{BNS-cc13, address = {Rome, Italy}, month = mar, year = 2013, volume = {7791}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {De{~}Bosschere, Koen and Jhala, Ranjit}, acronym = {{CC}'13}, booktitle = {{P}roceedings of the 22nd {I}nternational {C}onference on {C}ompiler {C}onstruction ({CC}'13)}, author = {Eberhard Bertsch and Mark-Jan Nederhof and Sylvain Schmitz}, title = {On {LR} Parsing with Selective Delays}, pages = {244-263}, url = {http://hal.archives-ouvertes.fr/hal-00769668}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BNS-cc13.pdf}, doi = {10.1007/978-3-642-37051-9_13}, abstract = {The paper investigates an extension of LR parsing that allows the delay of parsing decisions until a sufficient amount of context has been processed. We provide two characterizations for the resulting class of grammars, one based on grammar transformations, the other on the direct construction of a parser. We also report on experiments with a grammar collection.} }

@inproceedings{KS-fossacs13, address = {Rome, Italy}, month = mar, year = 2013, volume = {7794}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Pfenning, Frank}, acronym = {{FoSSaCS}'13}, booktitle = {{P}roceedings of the 16th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'13)}, author = {Karandikar, Prateek and Schmitz, Sylvain}, title = {The Parametric Ordinal-Recursive Complexity of {P}ost Embedding Problems}, pages = {273-288}, url = {http://arxiv.org/abs/1211.5259}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-fossacs13.pdf}, doi = {10.1007/978-3-642-37075-5_18}, abstract = {Post Embedding Problems are a family of decision problems based on the interaction of a rational relation with the subword embedding ordering, and are used in the literature to prove non multiply-recursive complexity lower bounds. We refine the construction of Chambart and Schnoebelen (LICS~2008) and prove parametric lower bounds depending on the size of the alphabet.} }

@mastersthesis{m2-halfon, author = {Halfon, Simon}, title = {Non Primitive Recursive Complexity Classes}, school = {{M}aster {P}arisien de {R}echerche en {I}nformatique, Paris, France}, type = {Rapport de {M}aster}, year = {2014}, month = sep, url = {http://www.lsv.fr/Publis/PAPERS/PDF/m2-halfon.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/m2-halfon.pdf}, note = {21~pages} }

@misc{reachard-18, author = {Finkel, Alain}, title = {REACHARD~-- Compte-rendu interm{\'e}diaire}, month = mar, year = {2013}, note = {9~pages}, type = {Contract Report}, howpublished = {Deliverable~D2 Reachard (ANR-11-BS02-001)} }

@misc{reachard-30, author = {Finkel, Alain}, title = {REACHARD~-- Compte-rendu interm{\'e}diaire}, month = feb, year = {2014}, note = {18~pages}, type = {Contract Report}, howpublished = {Deliverable~D3 Reachard (ANR-11-BS02-001)} }

@article{BKM-cc14, publisher = {Birkh{\"a}user}, journal = {Computational Complexity}, author = {Blondin, Michael and Krebs, Andreas and McKenzie, Pierre}, title = {The Complexity of Intersecting Finite Automata Having Few Final States}, volume = {25}, number = {4}, pages = {775-814}, month = dec, year = 2016, note = {To appear}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BKM-cc14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BKM-cc14.pdf}, doi = {10.1007/s00037-014-0089-9}, abstract = {The problem of determining whether several finite automata accept a word in common is closely related to the well-studied membership problem in transformation monoids. We raise the issue of limiting the number of final states in the automata intersection problem. For automata with two final states, we show the problem to be \(\oplus{L}\)-complete or NP-complete according to whether a nontrivial monoid other than a direct product of cyclic groups of order~2 is allowed in the automata. We further consider idempotent commutative automata and (Abelian, mainly) group automata with one, two, or three final states over a singleton or larger alphabet, elucidating (under the usual hypotheses on complexity classes) the complexity of the intersection nonemptiness and related problems in each case.} }

@article{LLV-tcs14, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Lange, Martin and Lozes, {\'E}tienne and Vargas{ }Guzm{\'a}n, Manuel}, title = {Model-checking process equivalences}, volume = {560}, number = {3}, year = {2014}, month = dec, pages = {326-347}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/LLV-tcs14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LLV-tcs14.pdf}, doi = {10.1016/j.tcs.2014.08.020}, abstract = {Process equivalences are formal methods that relate programs and systems which, informally, behave in the same way. Since there is no unique notion of what it means for two dynamic systems to display the same behaviour there are a multitude of formal process equivalences, ranging from bisimulation to trace equivalence, categorised in the linear-time branching-time spectrum.\par We present a logical framework based on an expressive modal fixpoint logic which is capable of defining many process equivalence relations: for each such equivalence there is a fixed formula which is satisfied by a pair of processes if and only if they are equivalent with respect to this relation.\par We explain how to do model checking for this logic in EXPTIME. This allows model checking technology to be used for process equivalence checking. We introduce two fragments of the logic for which it is possible to do model-checking in PTIME and PSPACE respectively, and show that the formulas that define the process equivalences we consider are in one of these fragments. This yields a generic proof technique for establishing the complexities of these process equivalences.\par Finally, we show how partial evaluation can be used to obtain decision procedures for process equivalences from the generic model checking scheme.} }

@article{JKS-lmcs14, journal = {Logical Methods in Computer Science}, author = {Jancar, Petr and Karandikar, Prateek and Schnoebelen, {\relax Ph}ilippe}, title = {On Reachability for Unidirectional Channel Systems Extended with Regular Tests}, year = {2015}, volume = 11, number = {{2:2}}, month = apr, nopages = {}, url = {http://arxiv.org/abs/1406.5067}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/JKS-lmcs14.pdf}, doi = {10.2168/LMCS-11(2:2)2015}, abstract = {{"}Unidirectional channel systems{"} (Chambart~\& Schnoebelen, CONCUR~2008) are finite-state systems where one-way communication from a Sender to a Receiver goes via one reliable and one unreliable unbounded fifo channel. While reachability is decidable for these systems, equipping them with the possibility of testing regular properties on the contents of channels makes it undecidable. Decidability is preserved when only emptiness and nonemptiness tests are considered: the proof relies on an elaborate reduction to a generalized version of Post's Embedding Problem.} }

@article{KKS-ipl14, publisher = {Elsevier Science Publishers}, journal = {Information Processing Letters}, author = {Karandikar, Prateek and Kufleitner, Manfred and Schnoebelen, {\relax Ph}ilippe}, title = {On the index of {S}imon's congruence for piecewise testability}, year = {2015}, month = apr, volume = {15}, number = {4}, pages = {515-519}, url = {http://arxiv.org/abs/1310.1278}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KKS-ipl14.pdf}, doi = {10.1016/j.ipl.2014.11.008}, abstract = {Simon's congruence, denoted \(\sim_{n}\), relates words having the same subwords of length up to~\(n\). We~show that, over a \(k\)-letter alphabet, the~number of words modulo~\(\sim_{n}\) is in \(2^{\Theta(n^{k-1}\cdot\log n)}\).} }

@article{HSS-lmcs14, journal = {Logical Methods in Computer Science}, author = {Haase, Christoph and Schmitz, Sylvain and Schnoebelen, {\relax Ph}ilippe}, title = {The Power of Priority Channel Systems}, year = {2014}, month = dec, volume = 10, number = {4:4}, nopages = {}, url = {http://arxiv.org/abs/1301.5500}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HSS-lmcs14.pdf}, doi = {10.2168/LMCS-10(4:4)2014}, abstract = {We introduce Priority Channel Systems, a new class of channel systems where messages carry a numeric priority and where higher-priority messages can supersede lower-priority messages preceding them in the fifo communication buffers. The decidability of safety and inevitability properties is shown via the introduction of a priority embedding, a well-quasi-ordering that has not previously been used in well-structured systems. We then show how Priority Channel Systems can compute Fast-Growing functions and prove that the aforementioned verification problems are \(\mathbf{F}_{\epsilon_{0}}\)-complete.} }

@inproceedings{schmitz-rp14, address = {Oxford, UK}, month = sep, year = 2014, volume = {8762}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Ouaknine, Jo{\"e}l and Potapov, Igor and Worrell, James}, acronym = {{RP}'14}, booktitle = {{P}roceedings of the 8th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'14)}, author = {Schmitz, Sylvain}, title = {Complexity Bounds for Ordinal-Based Termination}, pages = {1-19}, url = {http://arxiv.org/abs/1407.5896}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/schmitz-rp14.pdf}, doi = {10.1007/978-3-319-11439-2_1}, abstract = {`What more than its truth do we know if we have a proof of a theorem in a given formal system?' We examine Kreisel's question in the particular context of program termination proofs, with an eye to deriving complexity bounds on program running times.\par Our main tool for this are length function theorems, which provide complexity bounds on the use of well quasi orders. We illustrate how to prove such theorems in the simple yet until now untreated case of ordinals. We show how to apply this new theorem to derive complexity bounds on programs when they are proven to terminate thanks to a ranking function into some ordinal.} }

@inproceedings{LS-rp14, address = {Oxford, UK}, month = sep, year = 2014, volume = {8762}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Ouaknine, Jo{\"e}l and Potapov, Igor and Worrell, James}, acronym = {{RP}'14}, booktitle = {{P}roceedings of the 8th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'14)}, author = {Leroux, J{\'e}r{\^o}me and Schnoebelen, {\relax Ph}ilippe}, title = {On Functions Weakly Computable by {P}etri Nets and Vector Addition Systems}, pages = {190-202}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/LS-rp14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LS-rp14.pdf}, doi = { 10.1007/978-3-319-11439-2_15}, abstract = {We show that any unbounded function weakly computable by a Petri net or a VASS cannot be sublinear. This answers a long-standing folklore conjecture about weakly computing the inverses of some fast-growing functions. The proof relies on a pumping lemma for sets of runs in Petri nets or VASSes.} }

@inproceedings{HH-rp14, address = {Oxford, UK}, month = sep, year = 2014, volume = {8762}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Ouaknine, Jo{\"e}l and Potapov, Igor and Worrell, James}, acronym = {{RP}'14}, booktitle = {{P}roceedings of the 8th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'14)}, author = {Haase, Christoph and Halfon, Simon}, title = {Integer Vector Addition Systems with States}, pages = {112-124}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/HH-rp14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HH-rp14.pdf}, doi = {10.1007/978-3-319-11439-2_9}, abstract = {This paper studies reachability, coverability and inclusion problems for Integer Vector Addition Systems with States (\(\mathbb{Z}\)-VASS) and extensions and restrictions thereof. A~\(\mathbb{Z}\)-VASS comprises a finite-state controller with a finite number of counters ranging over the integers. Although it is folklore that reachability in \(\mathbb{Z}\)-VASS is NP-complete, it turns out that despite their naturalness, from a complexity point of view this class has received little attention in the literature. We fill this gap by providing an in-depth analysis of the computational complexity of the aforementioned decision problems. Most interestingly, it turns out that while the addition of reset operations to ordinary VASS leads to undecidability and Ackermann-hardness of reachability and coverability, respectively, they can be added to \(\mathbb{Z}\)-VASS while retaining NP-completeness of both coverability and reachability.} }

@article{FL-sosym14, publisher = {Springer}, journal = {Software~\& System Modeling}, author = {Finkel, Alain and Leroux, J{\'e}r{\^o}me}, title = {Recent and simple algorithms for {P}etri nets}, volume = 14, number = 2, year = {2015}, month = may, pages = {719-725}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/FL-sosym14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/FL-sosym14.pdf}, doi = {10.1007/s10270-014-0426-0}, abstract = {We show how inductive invariants can be used to solve coverability, boundedness and reachability problems for Petri nets. This approach provides algorithms that are conceptually simpler than previously pblished ones.} }

@article{EM-integers14, journal = {INTEGERS -- Electronic Journal of Combinatorial Number Theory}, author = {Elias, Yara and McKenzie, Pierre}, title = {On Generalized Addition Chains}, volume = 14, number = {A16}, nopages = {}, year = 2014, month = mar, url = {http://www.lsv.fr/Publis/PAPERS/PDF/EM-integers14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/EM-integers14.pdf}, abstract = {Given integers \(d \geq 1\), and \(g \geq 2\), a~\(g\)-addition chain for~\(d\) is a sequence of integers \(a_0 = 1\), \(a_1\), \(a_2\), ... , \(a_{r-1}\), \(a_r = d\) where \(a_i = a_{j_{1}} + a_{j_{2}} + \cdots + a_{j_{k}}\), with \(2 \leq k \leq g\), and \(0 \leq j_1 \leq j_2 \cdots j_k \leq i-1\). The length of a \(g\)-addition chain is~\(r\), the number of terms following~\(1\) in the sequence. We denote by~\(l_{g}(d)\) the length of a shortest addition chain for~\(d\). Many results have been established in the case \(g = 2\). Our aim is to establish the same sort of results for arbitrary fixed~\(g\). In~particular, we adapt methods for constructing \(g\)-addition chains when \(g = 2\) to the case \(g > 2\) and we study the asymptotic behavior of~\(l_g\).} }

@inproceedings{CKM-ncma14, address = {Kassel, Germany}, month = jul, year = 2014, volume = 304, series = {books@ocg.at}, publisher = {Austrian Computer Society}, editor = {Bensch, Suna and Freund, Rudolf and Otto, Friedrich}, acronym = {{NCMA}'14}, booktitle = {{P}roceedings of the 6th {W}orkshop on {N}on-{C}lassical {M}odels of {A}utomata and {A}pplications ({NCMA}'14)}, author = {Cadilhac, Micha{\"e}l and Krebs, Andreas and McKenzie, Pierre}, title = {Extremely uniform branching programs}, pages = {73-83}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CKM-ncma14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CKM-ncma14.pdf}, abstract = {We propose a new descriptive complexity notion of uniformity for branching programs solving problems defined on structured data. We observe that FO[=]-uniform (\(n\)-way) branching programs are unable to solve the tree evaluation problem studied by Cook, McKenzie, Wehr, Braverman and Santhanam because such programs possess a variant of their thriftiness property. Similarly, FO[=]-uniform (\(n\)-way) branching programs are unable to solve the P-complete GEN problem because such programs possess the incremental property studied by G{\'a}l, Kouck{\'y} and McKenzie.} }

@article{FL-is14, publisher = {Springer}, journal = {Informatik Spektrum}, author = {Finkel, Alain and Leroux, J{\'e}r{\^o}me}, title = {Neue, einfache {A}lgorithmen f{\"u}r {P}etrinetze}, volume = 37, number = {3}, month = jun, year = 2014, pages = {229-236}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/FL-is14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/FL-is14.pdf}, doi = {10.1007/s00287-013-0753-5}, abstract = {Wir zeigen, wie die Entscheidungsprobleme der {\"U}berdeckung, der Beschr{\"a}nktheit und der Erreichbarkeit mithilfe induktiver Invarianten einfacher l{\"o}sbar sind als mit herk{\"o}mmlichen Methoden} }

@inproceedings{CS-mfcs14, address = {Budapest, Hungary}, month = aug, year = 2014, volume = {8634}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {{\'E}sik, Zolt{\'a}n and Csuhaj{-}Varj{\'u}, Erzs{\'e}bet and Dietzfelbinger, Martin}, acronym = {{MFCS}'14}, booktitle = {{P}roceedings of the 39th {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'14)~-- {P}art~{I}}, author = {Courtois, Jean-Baptiste and Schmitz, Sylvain}, title = {Alternating Vector Addition Systems with States}, pages = {220-231}, url = {http://hal.inria.fr/hal-00980878}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CS-mfcs14.pdf}, doi = {10.1007/978-3-662-44522-8_19}, abstract = {Alternating vector addition systems are obtained by equipping vector addition systems with states (VASS) with 'fork' rules, and provide a natural setting for infinite-arena games played over a VASS. Initially introduced in the study of propositional linear logic, they have more recently gathered attention in the guise of \emph{multi-dimensional energy} games for quantitative verification and synthesis.\par We show that establishing who is the winner in such a game with a state reachability objective is 2-ExpTime-complete. As a further application, we show that the same complexity result applies to the problem of whether a VASS is simulated by a finite-state system.} }

@inproceedings{KS-dcfs2014, address = {Turku, Finland}, month = aug, year = 2014, volume = {8614}, series = {Lecture Notes in Computer Science}, publisher = {Springer-Verlag}, editor = {J{\"u}rgensen, Helmut and Karhum{\"a}ki, Juhani and Okhotin, Alexander}, acronym = {{DCFS}'14}, booktitle = {{P}roceedings of the 16th {W}orkshop on {D}escriptional {C}omplexity of {F}ormal {S}ystems ({DCFS}'14)}, author = {Karandikar, Prateek and Schnoebelen, {\relax Ph}ilippe}, title = {On the state complexity of closures and interiors of regular languages with subwords}, pages = {234-245}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-dcfs2014.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-dcfs2014.pdf}, doi = {10.1007/978-3-319-09704-6_21}, abstract = {We study the state complexity of the set of subwords and superwords of regular languages, and provide new lower bounds in the case of languages over a two-letter alphabet. We also consider the dual interior sets, for which the nondeterministic state complexity has a doubly-exponential upper bound. We prove a matching doubly-exponential lower bound for downward interiors in the case of an unbounded alphabet.} }

@article{KS-msttocs14, publisher = {Springer}, journal = {Theory of Computing Systems}, author = {Karandikar, Prateek and Schnoebelen, {\relax Ph}ilippe}, title = {Generalized {P}ost Embedding Problems}, year = {2015}, volume = 56, number = 4, pages = {697-716}, month = may, url = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-msttocs14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-msttocs14.pdf}, doi = {10.1007/s00224-014-9561-9}, abstract = {The Regular Post Embedding Problem extended with partial (co)directness is shown decidable. This extends to universal and\slash or counting versions. It is also shown that combining directness and codirectness in Post Embedding problems leads to undecidability.} }

@article{BFSP-tcs14, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Bouchy, Florent and Finkel, Alain and San{ }Pietro, Pierluigi}, title = {Dense-choice Counter Machines Revisited}, volume = {542}, month = jul, year = 2014, pages = {17-31}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFSP-tcs14.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BFSP-tcs14.pdf}, doi = {10.1016/j.tcs.2014.04.029}, abstract = {This paper clarifies the picture about Dense-choice Counter Machines (DCM), a less studied version of Counter Machines where counters range on a dense, rather than discrete, domain. The definition of DCM is revisited to make it extend (discrete) Counter Machines, and new undecidability and decidability results are proved. Using the first-order additive mixed theory of reals and integers, the paper presents a logical characterization of the sets of configurations reachable by reversal-bounded DCM. We also relate the DCM model to more common models of systems.} }

@inproceedings{BFM-icalp14, address = {Copenhagen, Denmark}, month = jul, year = 2014, volume = 8573, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Esparza, Javier and Fraigniaud, Pierre and Koutsoupias, Elias}, acronym = {{ICALP}'14}, booktitle = {{P}roceedings of the 41st {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'14)~-- {P}art~{II}}, author = {Blondin, Michael and Finkel, Alain and McKenzie, Pierre}, title = {Handling Infinitely Branching {WSTS}}, pages = {13-25}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BFM-icalp14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BFM-icalp14.pdf}, doi = {10.1007/978-3-662-43951-7_2}, abstract = {Most decidability results concerning well-structured transition systems apply to the \emph{finitely branching} variant. Yet some models (inserting automata, \(\omega\)-Petri nets,~...) are naturally infinitely branching. Here we develop tools to handle infinitely branching WSTS by exploiting the crucial property that in the (ideal) completion of a well-quasi-ordered set, downward-closed sets are finite unions of ideals. Then, using these tools, we derive decidability results and we delineate the undecidability frontier in the case of the termination, the control-state maintainability and the coverability problems. Coverability and boundedness under new effectivity conditions are shown decidable.} }

@inproceedings{DD-aiml14, address = {Groningen, The Netherlands}, month = aug, year = 2014, publisher = {College Publications}, editor = {Gor{\'e}, Rajeev and Kooi, Barteld P. and Kurucz, Agi}, acronym = {{AiML}'14}, booktitle = {{P}roceedings of the 10th {C}onference on {A}dvances in {M}odal {L}ogics ({AiML}'14)}, author = {Demri, St{\'e}phane and Deters, Morgan}, title = {The effects of modalities in separation logics (extended abstract)}, pages = {134-138}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-aiml14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-aiml14.pdf}, abstract = {Like modal logic, temporal logic, or description logic, separation logic has become a popular class of logical formalisms in computer science, conceived as assertion languages for Hoare-style proof systems with the goal to perform automatic program analysis. We present similarities with modal and temporal logics, and we present landmark results about decidability, complexity and expressive power.} }

@inproceedings{DD-csllics14, address = {Vienna, Austria}, month = jul, year = 2014, publisher = {ACM Press}, acronym = {{CSL\slash LICS}'14}, booktitle = {{P}roceedings of the Joint Meeting of the 23rd {EACSL} {A}nnual {C}onference on {C}omputer {S}cience {L}ogic and the 29th {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({CSL\slash LICS}'14)}, author = {Demri, St{\'e}phane and Deters, Morgan}, title = {Expressive Completeness of Separation Logic With Two Variables and No Separating Conjunction}, nopages = {}, chapter = {37}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-csllics14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-csllics14.pdf}, doi = {10.1145/2603088.2603142}, abstract = {We show that first-order separation logic with one record field restricted to two variables and the separating implication (no separating conjunction) is as expressive as weak second-order logic, substantially sharpening a previous result. Capturing weak second-order logic with such a restricted form of separation logic requires substantial updates to known proof techniques. We develop these, and as a by-product identify the smallest fragment of separation logic known to be undecidable: first-order separation logic with one record field, two variables, and no separating conjunction.} }

@inproceedings{Haase-csllics14, address = {Vienna, Austria}, month = jul, year = 2014, publisher = {ACM Press}, acronym = {{CSL\slash LICS}'14}, booktitle = {{P}roceedings of the Joint Meeting of the 23rd {EACSL} {A}nnual {C}onference on {C}omputer {S}cience {L}ogic and the 29th {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({CSL\slash LICS}'14)}, author = {Haase, Christoph}, title = {Subclasses of {P}resburger Arithmetic and the Weak {EXP} Hierarchy}, nopages = {}, chapter = 47, url = {http://arxiv.org/abs/1401.5266}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/Haase-csllics14.pdf}, doi = {10.1145/2603088.2603092}, abstract = {It is shown that for any fixed \(i>0\), the \(\Sigma_{i+1}\)-fragment of Presburger arithmetic, i.e., its restriction to \(i+1\) quantifier alternations beginning with an existential quantifier, is complete for \(\Sigma^{\textsc{EXP}}_{i}\), the \(i\)-th level of the weak EXP hierarchy, an~analogue to the polynomial-time hierarchy residing between \textsc{NEXP} and \textsc{EXPSPACE}. This result completes the computational complexity landscape for Presburger arithmetic, a~line of research which dates back to the seminal work by Fischer~\& Rabin in~1974. Moreover, we~apply some of the techniques developed in the proof of the lower bound in order to establish bounds on sets of naturals definable in the \(\Sigma_1\)-fragment of Presburger arithmetic: given a \(\Sigma_1\)-formula \(\Phi(x)\), it~is shown that the set of non-negative solutions is an ultimately periodic set whose period is at most doubly-exponentially and that this bound is tight.} }

@inproceedings{DGLM-csr14, address = {Moscow, Russia}, month = jun, year = 2014, volume = {8476}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Pin, Jean-{\'E}ric}, acronym = {{CSR}'14}, booktitle = {{P}roceedings of the 9th {I}nternational {C}omputer {S}cience {S}ymposium in {R}ussia ({CSR}'14)}, author = {Demri, St{\'e}phane and Galmiche, Didier and Larchey-Wendling, Dominique and M{\'e}ry, Daniel}, title = {Separation Logic with One Quantified Variable}, pages = {125-138}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DGLM-csr14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DGLM-csr14.pdf}, doi = {10.1007/978-3-319-06686-8_10}, abstract = {We investigate first-order separation logic with one record field restricted to a unique quantified variable (1SL1). Undecidability is known when the number of quantified variables is unbounded and the satisfiability problem is PSPACE-complete for the propositional fragment. We show that the satisfiability problem for 1SL1 is PSPACE-complete and we characterize its expressive power by showing that every formula is equivalent to a Boolean combination of atomic properties. This contributes to our understanding of fragments of first-order separation logic that can specify properties about the memory heap of programs with singly-linked lists. When the number of program variables is fixed, the complexity drops to polynomial time. All the fragments we consider contain the magic wand operator and first-order quantification over a single variable.} }

@inproceedings{BDD-frocos13, address = {Nancy, France}, month = sep, year = 2013, volume = 8152, series = {Lecture Notes in Artificial Intelligence}, publisher = {Springer}, editor = {Fontaine, Pascal and Ringeissen, Christophe and Schmidt, Renate A.}, acronym = {{FroCoS}'13}, booktitle = {{P}roceedings of the 9th {I}nternational {S}ymposium on {F}rontiers of {C}ombining {S}ystems ({FroCoS}'13)}, author = {Barrett, Clark and Demri, St{\'e}phane and Deters, Morgan}, title = {Witness runs for counter machines}, pages = {120-150}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/BDD-frocos13.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BDD-frocos13.pdf}, doi = {10.1007/978-3-642-40885-4_9}, abstract = {In this paper, we present recent results about the verification of counter machines by using decision procedures for Presburger arithmetic. We recall several known classes of counter machines for which the reachability sets are Presburger-definable as well as temporal logics with arithmetical constraints. We discuss issues related to flat counter machines, path schema enumeration, and the use of SMT solvers.} }

@inproceedings{Schmitz-rta14, address = {Vienna, Austria}, month = jul, year = 2014, volume = {8560}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Dowek, Gilles}, acronym = {{RTA\slash TLCA}'14}, booktitle = {{P}roceedings of the {J}oint 25th {I}nternational {C}onference on {R}ewriting {T}echniques and {A}pplications and 12th {I}nternational {C}onference on {T}yped {L}ambda-{C}alculi and {A}pplications ({RTA\slash TLCA}'14)}, author = {Schmitz, Sylvain}, title = {Implicational Relevance Logic is 2-{E}xp{T}ime-Complete}, pages = {395-409}, url = {http://arxiv.org/abs/1402.0705}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/Schmitz-rta14.pdf}, doi = {10.1007/978-3-319-08918-8_27}, abstract = {We show that provability in the implicational fragment of relevance logic is complete for doubly exponential time, using reductions to and from coverability in branching vector addition systems.} }

@inproceedings{LS-csllics14, address = {Vienna, Austria}, month = jul, year = 2014, publisher = {ACM Press}, acronym = {{CSL\slash LICS}'14}, booktitle = {{P}roceedings of the Joint Meeting of the 23rd {EACSL} {A}nnual {C}onference on {C}omputer {S}cience {L}ogic and the 29th {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({CSL\slash LICS}'14)}, author = {Lazi{\'c}, Ranko and Schmitz, Sylvain}, title = {Non-Elementary Complexities for Branching {VASS}, {MELL}, and Extensions}, nopages = {}, chapter = 61, url = {http://arxiv.org/abs/1401.6785}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LS-csllics14.pdf}, doi = {10.1145/2603088.2603129}, abstract = {We study the complexity of reachability problems on branching extensions of vector addition systems, which allows us to derive new non-elementary complexity bounds for fragments and variants of propositional linear logic. We show that provability in the multiplicative exponential fragment is Tower-hard already in the affine case---and hence non-elementary. We match this lower bound for the full propositional affine linear logic, proving its Tower-completeness. We also show that provability in propositional contractive linear logic is Ackermann-complete.} }

@inproceedings{AGHKO-fossacs14, address = {Grenoble, France}, month = apr, year = 2014, volume = {8412}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Muscholl, Anca}, acronym = {{FoSSaCS}'14}, booktitle = {{P}roceedings of the 17th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'14)}, author = {Antonopoulos, Timos and Gorogiannis, Nikos and Haase, Christoph and Kanovich, Max and Ouaknine, Jo{\"e}l}, title = {Foundations for Decision Problems in Separation Logic with General Inductive Predicates}, pages = {411-425}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/AGHKO-fossacs14.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/AGHKO-fossacs14.pdf}, doi = {10.1007/978-3-642-54830-7_27}, abstract = {We establish foundational results on the computational complexity of deciding entailment in Separation Logic with general inductive predicates whose underlying base language allows for pure formulas, pointers and existentially quantified variables. We show that entailment is in general undecidable, and \textsc{ExpTime}-hard in a fragment recently shown to be decidable by Iosif~\emph{et~al.} Moreover, entailment in the base language is \(\Pi_2^{\text{P}}\)-complete, the upper bound even holds in the presence of list predicates. We additionally show that entailment in essentially any fragment of Separation Logic allowing for general inductive predicates is intractable even when strong syntactic restrictions are imposed.} }

@inproceedings{Lozes-fics15, address = {Berlin, Germany}, month = sep, year = 2015, volume = 191, series = {Electronic Proceedings in Theoretical Computer Science}, editor = {Matthes, Ralph and Mio, Matteo}, acronym = {{FICS}'15}, booktitle = {{P}roceedings of the 10th {W}orkshop on {F}ixed {P}oints in {C}omputer {S}cience ({FICS}'15)}, author = {Lozes, {\'{E}}tienne}, title = {A Type-Directed Negation Elimination}, pages = {132-142}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/Lozes-fics15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/Lozes-fics15.pdf}, doi = {10.4204/EPTCS.191.12}, abstract = {In the modal mu-calculus, a formula is well-formed if each recursive variable occurs underneath an even number of negations. By means of De Morgan's laws, it is easy to transform any well-formed formula into an equivalent formula without negations - its negation normal form. Moreover, if the formula is of size n, its negation normal form of is of the same size O(n). The full modal mu-calculus and the negation normal form fragment are thus equally expressive and concise. In this paper we extend this result to the higher-order modal fixed point logic (HFL), an extension of the modal mu-calculus with higher-order recursive predicate transformers. We present a procedure that converts a formula into an equivalent formula without negations of quadratic size in the worst case and of linear size when the number of variables of the formula is fixed.} }

@article{LV-scp15, publisher = {Elsevier Science Publishers}, journal = {Science of Computer Programming}, author = {Lozes, {\'{E}}tienne and Villard, Jules}, title = {Shared contract-obedient channels}, year = 2015, month = mar, volume = {100}, pages = {28-60}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/LV-scp15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LV-scp15.pdf}, doi = {10.1016/j.scico.2014.09.008}, abstract = {Recent advances in the formal verification of message-passing programs are based on proving that programs correctly implement a given protocol. Many existing verification techniques for message-passing programs assume that at most one thread may attempt to send or receive on a channel endpoint at any given point in time, and expressly forbid endpoint sharing. Approaches that do allow such sharing often do not prove that channels obey their protocols. In this paper, we identify two principles that can guarantee obedience to a communication protocol even in the presence of endpoint sharing. Firstly, threads may concurrently use an endpoint in any way that does not advance the state of the protocol. Secondly, threads may compete for receiving on an endpoint provided that the successful reception of the message grants them ownership of that endpoint retrospectively. We develop a program logic based on separation logic that unifies these principles and allows fine-grained reasoning about endpoint-sharing programs. We demonstrate its applicability on a number of examples. The program logic is shown sound against an operational semantics of programs, and proved programs are guaranteed to follow the given protocols and to be free of data races, memory leaks, and communication errors.} }

@inproceedings{LL-fct15, address = {Gda{\'{n}}sk, Poland}, month = aug, year = 2015, volume = 9210, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Kosowski, Adrian and Walukiewicz, Igor}, acronym = {{FCT}'15}, booktitle = {{P}roceedings of the 20th {I}nternational {S}ymposium on {F}undamentals of {C}omputation {T}heory ({FCT}'15)}, author = {Lange, Martin and Lozes, {\'{E}}tienne}, title = {Conjunctive Visibly-Pushdown Path Queries}, pages = {327-338}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/LL-fct15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LL-fct15.pdf}, doi = {10.1007/978-3-319-22177-9_25}, abstract = {Weinvestigateanextensionofconjunctiveregularpathqueries in which path properties and path relations are defined by visibly push- down automata. We study the problem of query evaluation for extended conjunctive visibly pushdown path queries and their subclasses, and give a complete picture of their combined and data complexity. In particular, we introduce a weaker notion called extended conjunctive reachability queries for which query evaluation has a polynomial data complexity. We also show that query containment is decidable in 2-EXPTIME for (non-extended) conjunctive visibly pushdown path queries.} }

@article{KNS-tcs2015, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Karandikar, Prateek and Niewerth, Matthias and Schnoebelen, {\relax Ph}ilippe}, title = {On the state complexity of closures and interiors of regular languages with subwords and superwords}, volume = {610}, number = {A}, pages = { 91-107}, year = {2016}, month = jan, url = {http://www.lsv.fr/Publis/PAPERS/PDF/KNS-tcs15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KNS-tcs15.pdf}, doi = {10.1016/j.tcs.2015.09.028}, abstract = {The downward and upward closures of a regular language~\(L\) are obtained by collecting all the subwords and superwords of its elements, respectively. The downward and upward interiors of~\(L\) are obtained dually by collecting words having all their subwords and superwords in~\(L\), respectively.\par We provide lower and upper bounds on the size of the smallest automata recognizing these closures and interiors. We also consider the computational complexity of decision problems for closures of regular languages.} }

@article{HK-ipl15, publisher = {Elsevier Science Publishers}, journal = {Information Processing Letters}, author = {Haase, Christoph and Kiefer, Stefan}, title = {The Complexity of the \(K\)th Largest Subset Problem and Related Problems}, volume = {116}, number = {2}, pages = {111-115}, month = feb, year = {2016}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/HK-ipl15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HK-ipl15.pdf}, doi = {10.1016/j.ipl.2015.09.015}, abstract = {We show that the \textsc{\(K\)th largest subset} problem and the \textsc{\(K\)th largest \(m\)-tuple} problem are in PP and hard for PP under polynomial-time Turing reductions. Several problems from the literature were previously shown NP-hard via reductions from those two problems, and by our main result they become PP-hard as well. We also provide complementary PP-upper bounds for some of them.} }

@inproceedings{KS-fsttcs15, address = {Bangalore, India}, month = dec, year = 2015, volume = {45}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Harsha, Prahladh and Ramalingam, G.}, acronym = {{FSTTCS}'15}, booktitle = {{P}roceedings of the 35th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'15)}, author = {Karandikar, Prateek and Schnoebelen, {\relax Ph}ilippe}, title = {Decidability in the logic of subsequences and supersequences}, pages = {84-97}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-fsttcs15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-fsttcs15.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2015.84}, abstract = {We consider first-order logics of sequences ordered by the subsequence ordering, aka sequence embedding. We show that the \(\Sigma_{2}\)-theory is undecidable, answering a question left open by Kuske. Regarding fragments with a bounded number of variables, we show that the \(\textsf{FO}^{2}\)-theory is decidable while the \(\textsf{FO}^{3}\)-theory is undecidable.} }

@phdthesis{karandikar-phd15, author = {Karandikar, Prateek}, title = {Subwords: automata, embedding problems, and verification}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France and Chennai Mathematical Institute, India}, type = {Th{\`e}se de doctorat}, year = 2015, month = feb, url = {http://www.lsv.fr/Publis/PAPERS/PDF/karandikar-phd15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/karandikar-phd15.pdf} }

@inproceedings{LS-rp15, address = {Warsaw, Poland}, month = sep, year = 2015, volume = {9328}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Boja{\'n}czyk, Miko{\l}aj and Lasota, S{\l}awomir and Potapov, Igor}, acronym = {{RP}'15}, booktitle = {{P}roceedings of the 9th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'15)}, author = {Lazi{\'c}, Ranko and Schmitz, Sylvain}, title = {The Ideal View on {R}ackoff's Coverability Technique}, pages = {76-88}, url = {https://hal.inria.fr/hal-01176755}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LS-rp15.pdf}, doi = {10.1007/978-3-319-24537-9_8}, abstract = {Rackoff's small witness property for the coverability problem is the standard means to prove tight upper bounds in vector addition systems (VAS) and many extensions. We show how to derive the same bounds directly on the computations of the VAS instantiation of the generic backward coverability algorithm. This relies on a dual view of the algorithm using ideal decompositions of downwards-closed sets, which exhibits a key structural invariant in the VAS case. The same reasoning readily generalises to several VAS extensions.} }

@inproceedings{JLS-icalp15, address = {Kyoto, Japan}, month = jul, year = 2015, volume = {9135}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Halld{\'o}rsson, Magnus M. and Iwama, Kazuo and Kobayashi, Naoki and Speckmann, Bettina}, acronym = {{ICALP}'15}, booktitle = {{P}roceedings of the 42nd {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'15)~-- {P}art~{II}}, author = {Jurdzi{\'n}ski, Marcin and Lazi{\'c}, Ranko and Schmitz, Sylvain}, title = {Fixed-Dimensional Energy Games are in Pseudo Polynomial Time}, pages = {260-272}, url = {http://arxiv.org/abs/1502.06875}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/JLS-arxiv15.pdf}, doi = {10.1007/978-3-662-47666-6_21}, abstract = {We generalise the hyperplane separation technique (Chatterjee and Velner,~2013) from multi-dimensional mean-payoff to energy games, and achieve an algorithm for solving the latter whose running time is exponential only in the dimension, but not in the number of vertices of the game graph. This answers an open question whether energy games with arbitrary initial credit can be solved in pseudo-polynomial time for fixed dimensions~\(3\) or larger (Chaloupka,~2013). It~also improves the complexity of solving multi-dimensional energy games with given initial credit from non-elementary (Br\'azdil, Jan\v{c}ar, and Ku\v{c}era,~2010) to 2EXPTIME, thus establishing their 2EXPTIME-completeness.} }

@article{DD-jlc15, publisher = {Oxford University Press}, journal = {Journal of Logic and Computation}, author = {Demri, St{\'e}phane and Deters, Morgan}, title = {Temporal Logics on Strings with Prefix Relation}, year = 2016, volume = {26}, number = {3}, pages = {989-1017}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-jlc15-v2.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-jlc15-v2.pdf}, doi = {10.1093/logcom/exv028}, abstract = {We show that linear-time temporal logic over concrete domains made of finite strings and the prefix relation admits a PSpace-complete satisfiability problem. Actually, we extend a known result with the concrete domain made of the set of natural numbers and the greater than relation (corresponding to the singleton alphabet case) and we solve an open problem mentioned in several publications. Since the prefix relation is not a total ordering, it~is not possible to take advantage of existing techniques dedicated to temporal logics with concrete domains that are essentially linearly ordered structures. Instead, we introduce an adequate encoding of string constraints into length constraints that allows us to reduce the problem on strings to the problem on natural numbers. To~do~so, we~also propose an extended version of the logic on strings that is able to compare lengths of longest common prefixes and for which the satisfiability problem is shown in PSpace. Finally, we show how to lift the result for the branching-time case in order to get decidability when the underlying temporal logic is~CTL\textsuperscript*.} }

@inproceedings{HK-icalp15, address = {Kyoto, Japan}, month = jul, year = 2015, volume = {9135}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Halld{\'o}rsson, Magnus M. and Iwama, Kazuo and Kobayashi, Naoki and Speckmann, Bettina}, acronym = {{ICALP}'15}, booktitle = {{P}roceedings of the 42nd {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'15)~-- {P}art~{II}}, author = {Haase, Christoph and Kiefer, Stefan}, title = {The Odds of Staying on Budget}, pages = {234-246}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/HK-icalp15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HK-icalp15.pdf}, doi = {10.1007/978-3-662-47666-6_19}, abstract = {Given Markov chains and Markov decision processes (MDPs) whose transitions are labelled with non-negative integer costs, we study the computational complexity of deciding whether the probability of paths whose accumulated cost satisfies a Boolean combination of inequalities exceeds a given threshold. For acyclic Markov chains, we show that this problem is PP-complete, whereas it is hard for the POSSLP problem and in PS PACE for general Markov chains. Moreover, for acyclic and general MDPs, we prove PSPACE- and EXP-completeness, respectively. Our results have direct implications on the complexity of computing reward quantiles in succinctly represented stochastic systems.} }

@inproceedings{LS-lics15, address = {Kyoto, Japan}, month = jul, year = 2015, publisher = {{IEEE} Press}, acronym = {{LICS}'15}, booktitle = {{P}roceedings of the 30th {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'15)}, author = {Leroux, J{\'e}r{\^o}me and Schmitz, Sylvain}, title = {Demystifying Reachability in Vector Addition Systems}, pages = {56-67}, url = {http://arxiv.org/abs/1503.00745}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LS-arxiv15.pdf}, doi = {10.1109/LICS.2015.1}, abstract = {More than 30 years after their inception, the decidability proofs for reachability in vector addition systems (VAS) still retain much of their mystery. These proofs rely crucially on a decomposition of runs successively refined by Mayr, Kosaraju, and Lambert, which appears rather magical, and for which no complexity upper bound is known.\par We first offer a justification for this decomposition technique, by showing that it emerges naturally in the study of the ideals of a well quasi ordering of VAS runs. In a second part, we apply recent results on the complexity of termination thanks to well quasi orders and well orders to obtain fast-growing complexity upper bounds for the decomposition algorithms, thus providing the first known upper bounds for general VAS reachability.} }

@inproceedings{BFGHM-lics15, address = {Kyoto, Japan}, month = jul, year = 2015, publisher = {{IEEE} Press}, acronym = {{LICS}'15}, booktitle = {{P}roceedings of the 30th {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'15)}, author = {Blondin, Michael and Finkel, Alain and G{\"o}ller, Stefan and Haase, Christoph and McKenzie, Pierre}, title = {Reachability in Two-Dimensional Vector Addition Systems with States is {PSPACE}-Complete}, pages = {32-43}, url = {http://arxiv.org/abs/1412.4259}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BFGHM-lics15-long.pdf}, doi = {10.1109/LICS.2015.14}, abstract = {Determining the complexity of the reachability problem for vector addition systems with states (VASS) is a long-standing open problem in computer science. Long known to be decidable, the problem to this day lacks any complexity upper bound whatsoever. In this paper, reachability for two-dimensional VASS is shown PSPACE-complete. This improves on a previously known doubly exponential time bound established by Howell, Rosier, Huynh and Yen in~1986. The coverability and boundedness problems are also noted to be PSPACE-complete. In addition, some complexity results are given for the reachability problem in two-dimensional VASS and in integer VASS when numbers are encoded in unary.} }

@article{DDS-ic15, publisher = {Elsevier Science Publishers}, journal = {Information and Computation}, author = {Demri, St{\'e}phane and Dhar, Amit Kumar and Sangnier, Arnaud}, title = {Taming Past {LTL} and Flat Counter Systems}, volume = {242}, month = jun, year = 2015, pages = {306-339}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DDS-ic15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DDS-ic15.pdf}, doi = {10.1016/j.ic.2015.03.007}, abstract = {Reachability and LTL model-checking problems for flat counter systems are known to be decidable but whereas the reachability problem can be shown in NP, the best known complexity upper bound for the latter problem is made of a tower of several exponentials. Herein, we show that this problem is only NP-complete even if LTL admits past-time operators and arithmetical constraints on counters. As far as past-time operators are concerned, their addition to LTL immediately leads to complications and hence an NP upper bound cannot be deduced by translating formulae into LTL and studying the problem only for this latter logic. Actually, the NP upper bound is shown by adequately combining a new stuttering theorem for Past LTL and the property of small integer solutions for quantifier-free Presburger formulae. This latter complexity bound extends known and recent results on model-checking weak Kripke structures with LTL formulae as well as reachability problems for flat counter systems. We also provide other complexity results obtained by restricting further the class of flat counter systems.} }

@article{LS-tocl15, publisher = {ACM Press}, journal = {ACM Transactions on Computational Logic}, author = {Lazi{\'c}, Ranko and Schmitz, Sylvain}, title = {Non-Elementary Complexities for Branching~{VASS}, {MELL}, and Extensions}, volume = {16}, number = {3:20}, nopages = {}, month = jul, year = 2015, url = {http://arxiv.org/abs/1401.6785}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/LS-tocl15.pdf}, doi = {10.1145/2733375}, abstract = {We study the complexity of reachability problems on branching extensions of vector addition systems, which allows us to derive new non-elementary complexity bounds for fragments and variants of propositional linear logic. We show that provability in the multiplicative exponential fragment is Tower-hard already in the affine case---and hence non-elementary. We match this lower bound for the full propositional affine linear logic, proving its Tower-completeness. We also show that provability in propositional contractive linear logic is Ackermann-complete.} }

@article{Schmitz-jsl15, publisher = {Association for Symbolic Logic}, journal = {Journal of Symbolic Logic}, author = {Schmitz, Sylvain}, title = {Implicational Relevance Logic is \(2\)-{ExpTime}-Complete}, volume = {81}, number = {2}, pages = {641-661}, month = jun, year = 2016, url = {http://arxiv.org/abs/1402.0705}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/Schmitz-jsl15.pdf}, doi = {10.1017/jsl.2015.7}, abstract = {We show that provability in the implicational fragment of relevance logic is complete for doubly exponential time, using reductions to and from coverability in branching vector addition systems.} }

@techreport{KNS-arxiv14, author = {Karandikar, Prateek and Niewerth, Matthias and Schnoebelen, {\relax Ph}ilippe}, title = {On the state complexity of closures and interiors of regular languages with subwords}, institution = {Computing Research Repository}, number = {1406.0690}, year = {2014}, month = nov, type = {Research Report}, url = {http://arxiv.org/abs/1406.0690}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KNS-arxiv14.pdf}, note = {24~pages}, abstract = {We study the state complexity of the set of subwords and superwords of regular languages, and provide new lower bounds in the case of languages over a two-letter alphabet. We also consider the dual interior sets, for which the nondeterministic state complexity has a doubly-exponential upper bound. We prove a matching doubly-exponential lower bound for downward interiors in the case of an unbounded alphabet.} }

@article{DD-jancl15, publisher = {Taylor \& Francis}, journal = {Journal of Applied Non-Classical Logics}, author = {Demri, St{\'e}phane and Deters, Morgan}, title = {Separation Logics and Modalities: A~Survey}, volume = 25, number = 1, pages = {50-99}, year = 2015, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-jancl15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-jancl15.pdf}, doi = {10.1080/11663081.2015.1018801}, abstract = {Like modal logic, temporal logic, or description logic, separation logic has become a popular class of logical formalisms in computer science, conceived as assertion languages for Hoare-style proof systems with the goal to perform automatic program analysis. In a broad sense, separation logic is often understood as a programming language, an assertion language and a family of rules involving Hoare triples. In this survey, we present similarities between separation logic as an assertion language and modal and temporal logics. Moreover, we propose a selection of landmark results about decidability, complexity and expressive power.} }

@article{DD-tocl15, publisher = {ACM Press}, journal = {ACM Transactions on Computational Logic}, author = {Demri, St{\'e}phane and Deters, Morgan}, title = {Two-variable separation logic and its inner circle}, volume = 16, number = {2:15}, nopages = {}, month = mar, year = 2015, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-tocl15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-tocl15.pdf}, doi = {10.1145/2724711}, abstract = {Separation logic is a well-known assertion language for Hoare-style proof systems. We show that first-order separation logic with a unique record field restricted to two quantified variables and no program variables is undecidable. This is among the smallest fragments of separation logic known to be undecidable, and this contrasts with decidability of two-variable first-order logic. We also investigate its restriction by dropping the magic wand connective, known to be decidable with non-elementary complexity, and we show that the satisfiability problem with only two quantified variables is not yet elementary recursive. Furthermore, we establish insightful and concrete relationships between two-variable separation logic and propositional in- terval temporal logic (PITL), data logics, and modal logics, providing an inner circle of closely-related logics.} }

@misc{qcover16, author = {Blondin, Michael and Finkel, Alain and Haase, Christoph and Haddad, Serge}, title = {{QCover: an efficient coverability verifier for discrete and continuous Petri nets}}, url = {https://github.com/blondimi/qcover}, year = {2016} }

@article{BCEZ-dmtcs2016, journal = {Discrete Mathematics \& Theoretical Computer Science}, author = {Brough, Tara and Ciobanu, Laura and Elder, Murray and Zetzsche, Georg}, title = {{Permutations of context-free, ET0L and indexed languages}}, volume = {17}, number = {3}, year = {2016}, month = may, pages = {167-178}, url = {https://dmtcs.episciences.org/2164}, pdf = {https://arxiv.org/pdf/1604.05431.pdf} }

@inproceedings{BHMRZ-fossacs17, address = {Uppsala, Sweden}, month = apr, year = 2017, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Esparza, Javier and Murawski, Andrzej}, acronym = {{FoSSaCS}'17}, booktitle = {{P}roceedings of the 20th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'17)}, author = {Bouyer, Patricia and Hofman, Piotr and Markey, Nicolas and Randour, Mickael and Zimmermann, Martin}, title = {Bounding Average-energy Games}, pages = {179-195}, url = {https://arxiv.org/abs/1610.07858}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BHMRZ-fossacs17.pdf}, doi = {10.1007/978-3-662-54458-7_11}, abstract = {We consider average-energy games, where the goal is to minimize the long-run average of the accumulated energy. Decidability of average-energy games with a lower-bound constraint on the energy level (but no upper bound) is an open problem; in particular, there is no known upper bound on the memory that is required for winning strategies. By reducing average-energy games with lower-bounded energy to infinite-state mean-payoff games and analyzing the frequency of low-energy configurations, we show an almost tight doubly-exponential upper bound on the necessary memory, and that the winner of average-energy games with lower-bounded energy can be determined in doubly-exponential time. We also prove EXPSPACE-hardness of this problem. Finally, we consider multi-dimensional extensions of all types of average-energy games: without bounds, with only a lower bound, and with both a lower and an upper bound on the energy. We show that the fully-bounded version is the only case to remain decidable in multiple dimensions.} }

@inproceedings{BGHH-stacs17, address = {Hannover, Germany}, month = mar, year = 2017, volume = {}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Vall{\'e}e, Brigitte and Vollmer, Heribert}, acronym = {{STACS}'17}, booktitle = {{P}roceedings of the 34th {A}nnual {S}ymposium on {T}heoretical {A}spects of {C}omputer {S}cience ({STACS}'17)}, author = {B{\"o}hm, Stanislav and G{\"o}ller, Stefan and Halfon, Simon and Hofman, Piotr}, title = {On B{\"u}chi one-counter automata}, pages = {14:1-14:13}, url = {http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=7019}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2017/7019/pdf/LIPIcs-STACS-2017-14.pdf}, doi = {10.4230/LIPIcs.STACS.2017.14}, abstract = {Equivalence of deterministic pushdown automata is a famous problem in theoretical computer science whose decidability has been shown by S{\'e}nizergues. Our first result shows that decidability no longer holds when moving from finite words to infinite words. This solves an open problem that has recently been raised by L{\"o}ding. In fact, we show that already the equivalence problem for deterministic B{\"u}chi one-counter automata is undecidable. Hence, the decidability border is rather tight when taking into account a recent result by L{\"o}ding and Repke that equivalence of deterministic weak parity pushdown automata (a subclass of deterministic B{\"u}chi pushdown automata) is decidable. Another known result on finite words is that the universality problem for vector addition systems is decidable. We show undecidability when moving to infinite words. In fact, we prove that already the universality problem for nondeterministic B{\"u}chi one-counter nets (or equivalently vector addition systems with one unbounded dimension) is undecidable.} }

@inproceedings{CG-stacs17, address = {Hannover, Germany}, month = mar, year = 2017, volume = {}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Vall{\'e}e, Brigitte and Vollmer, Heribert}, acronym = {{STACS}'17}, booktitle = {{P}roceedings of the 34th {A}nnual {S}ymposium on {T}heoretical {A}spects of {C}omputer {S}cience ({STACS}'17)}, author = {Carayol, Arnaud and G{\"o}ller, Stefan}, title = {On long words avoiding Zimin patterns}, pages = {19:1-19:13}, url = {http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=7014}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2017/7014/pdf/LIPIcs-STACS-2017-19.pdf}, doi = {10.4230/LIPIcs.STACS.2017.19}, abstract = {A pattern is encountered in a word if some infix of the word is the image of the pattern under some non-erasing morphism. A pattern p is unavoidable if, over every finite alphabet, every sufficiently long word encounters p. A theorem by Zimin and independently by Bean, Ehrenfeucht and McNulty states that a pattern over n distinct variables is unavoidable if, and only if, p itself is encountered in the n-th Zimin pattern. Given an alphabet size k, we study the minimal length f(n,k) such that every word of length f(n,k) encounters the n-th Zimin pattern. It is known that f is upper-bounded by a tower of exponentials. Our main result states that f(n,k) is lower-bounded by a tower of n-3 exponentials, even for k=2. To the best of our knowledge, this improves upon a previously best-known doubly-exponential lower bound. As a further result, we prove a doubly-exponential upper bound for encountering Zimin patterns in the abelian sense.} }

@inproceedings{LZ-stacs17, address = {Hannover, Germany}, month = mar, year = 2017, volume = {}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Vall{\'e}e, Brigitte and Vollmer, Heribert}, acronym = {{STACS}'17}, booktitle = {{P}roceedings of the 34th {A}nnual {S}ymposium on {T}heoretical {A}spects of {C}omputer {S}cience ({STACS}'17)}, author = {Lohrey, Markus and Zetzsche, Georg}, title = {The Complexity of Knapsack in Graph Groups}, pages = {52:1-52:14}, doi = {10.4230/LIPIcs.STACS.2017.52}, abstract = {Myasnikov et al. have introduced the knapsack problem for arbitrary finitely generated groups. In LohreyZ16 the authors proved that for each graph group, the knapsack problem can be solved in NP. Here, we determine the exact complexity of the problem for every graph group. While the problem is TC0-complete for complete graphs, it is LogCFL-complete for each (non-complete) transitive forest. For every remaining graph, the problem is NP-complete.} }

@phdthesis{blondin-phd2016, author = {Blondin, Michael}, title = {Algorithmique et complexit{\'e} des syst{\`e}mes {\`a} compteurs}, school = {Laboratoire Sp{\'e}cification et V{\'e}rification, ENS Cachan, France and Universit{\'e} de Montr{\'e}al}, type = {Th{\`e}se de doctorat}, year = {2016}, month = jun, url = {https://tel.archives-ouvertes.fr/tel-01359000/} }

@book{DGL-cup2016, author = {Demri, St{\'e}phane and Goranko, Valentin and Lange, Martin}, title = {{T}emporal {L}ogics in {C}omputer {S}cience}, publisher = {Cambridge University Press}, series = {Cambridge Tracts in Theoretical Computer Science}, volume = {58}, year = {2016}, month = oct, url = {http://www.cambridge.org/9781107028364}, isbn = {9781107028364} }

@inproceedings{HHKLL-syncop16, address = {Eindhoven, The Netherlands}, month = apr, year = 2016, volume = 220, series = {Electronic Proceedings in Theoretical Computer Science}, acronym = {{C}assting/{SYNCOP}'16}, booktitle = {{P}roceedings of the {C}assting {W}orkshop on {G}ames for the {S}ynthesis of {C}omplex {S}ystems and 3rd {I}nternational {W}orkshop on {S}ynthesis of {C}omplex {P}arameters ({C}assting/{SYNCOP}'16)}, author = {Hutagalung, Milka and Hundeshagen, Norbert and Kuske, Dietrich and Lange, Martin and Lozes, {\'{E}}tienne}, title = {Two-Buffer Simulation Games}, pages = {213-227}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/HHKLL-syncop16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HHKLL-syncop16.pdf}, doi = {10.4204/EPTCS.220.3}, abstract = {We consider simulation games played between Spoiler and Duplicator on two B{\"u}chi automata in which the choices made by Spoiler can be buffered by Duplicator in two different buffers before she executes them on her structure. Previous work on such games using a single buffer has shown that they are useful to approximate language inclusion problems. We study the decidability and complex- ity and show that games with two buffers can be used to approximate corresponding problems on finite transducers, i.e. the inclusion problem for rational relations over infinite words.} }

@inproceedings{HHKLL-gandalf16, address = {Catania, Italy}, month = sep, year = 2016, volume = {226}, series = {Electronic Proceedings in Theoretical Computer Science}, editor = {Cantone, Domenico and Delzanno, Giorgio}, acronym = {{GandALF}'16}, booktitle = {{P}roceedings of the 7th {I}nternational {S}ymposium on {G}ames, {A}utomata, {L}ogics, and {F}ormal {V}erification ({GandALF}'16)}, author = {Hutagalung, Milka and Hundeshagen, Norbert and Kuske, Dietrich and Lange, Martin and Lozes, {\'{E}}tienne}, title = {Multi-Buffer Simulations for Trace Language Inclusion}, pages = {213-227}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/HHKLL-gandalf16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HHKLL-gandalf16.pdf}, doi = {10.4204/EPTCS.226.15}, abstract = {We consider simulation games played between Spoiler and Duplicator on two B{\"u}chi automata in which the choices made by Spoiler can be buffered by Duplicator in several buers before she executes them on her structure. We show that the simulation games are useful to approximate the inclusion of trace closures of languages accepted by finite-state automata, which is known to be undecidable. We study the decidability and complexity and show that the game with bounded buffers can be decided in polynomial time, whereas the game with one unbounded and one bounded buffer is highly undecidable. We also show some sufficient conditions on the automata for Duplicator to win the game (with unbounded buffers).} }

@techreport{arxiv16-BFMK, author = {Blondin, Michael and Finkel, Alain and McKenzie, Pierre}, title = {Well Behaved Transition Systems}, institution = {Computing Research Repository}, number = {1608.02636}, year = {2016}, month = aug, type = {Research Report}, url = {http://arxiv.org/abs/1608.02636}, pdf = {http://arxiv.org/abs/1608.02636}, note = {18~pages}, abstract = {The well-quasi-ordering (i.e., a well-founded quasi-ordering such that all antichains are finite) that defines well-structured transition systems (WSTS) is shown not to be the weakest hypothesis that implies decidability of the coverability problem. We show coverability decidable for monotone transition systems that only require the absence of infinite antichains and call well behaved transitions systems (WBTS) the new strict superclass of the class of WSTS that arises. By contrast, we confirm that boundedness and termination are undecidable for WBTS under the usual hypotheses, and show that stronger monotonicity conditions can enforce decidability. Proofs are similar or even identical to existing proofs but the surprising message is that a hypothesis implicitely assumed minimal for twenty years in the theory of WSTS can meaningfully be relaxed, allowing more orderings to be handled in an abstract way.} }

@article{ADFLP-fi2016, publisher = {{IOS} Press}, journal = {Fundamenta Informaticae}, author = {Abdulla, Parosh Aziz and Demri, St{\'e}phane and Finkel, Alain and Leroux, J{\'e}r{\^o}me and Potapov, Igor}, editor = {Abdulla, Parosh Aziz and Demri, St{\'e}phane and Finkel, Alain and Leroux, J{\'e}r{\^o}me and Potapov, Igor}, number = {3--4}, title = {Selected papers of Reachability Problems Workshop 2012 (Bordeaux) and 2013 (Uppsala)}, url = {http://content.iospress.com/journals/fundamenta-informaticae/143/3-4}, volume = {143}, year = {2016} }

@proceedings{BDM-aiml16, title = {{P}roceedings of the 11th {C}onference on {A}dvances in {M}odal {L}ogic ({AiML}'16)}, booktitle = {{P}roceedings of the 11th {C}onference on {A}dvances in {M}odal {L}ogic ({AiML}'16)}, acronym = {{AiML}'16}, editor = {Beklemishev, Lev and Demri, St{\'e}phane and Mat{\'e}, Andr{\'a}s}, publisher = {College Publications}, year = 2016, month = sep, address = {Budapest, Hungary}, url = {http://www.collegepublications.co.uk/aiml/?00008} }

@inproceedings{Finkel-rp16, address = {Aalborg, Denmark}, month = sep, year = 2016, volume = {9899}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Larsen, Kim G. and Srba, Ji{\v{r}}{\'\i}}, acronym = {{RP}'16}, booktitle = {{P}roceedings of the 10th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'16)}, author = {Finkel, Alain}, title = {The Ideal Theory for {WSTS}}, pages = {1-22}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/Finkel-rp16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/Finkel-rp16.pdf}, doi = {10.1007/978-3-319-45994-3_1}, abstract = {We begin with a survey on well structured transition systems and, in particular, we present the ideal framework [FG09a, BFM14] which was recently used to obtain new deep results on Petri nets and extensions. We argue that the theory of ideals prompts a renewal of the theory of WSTS by providing a way to define a new class of monotonic systems, the so-called Well Behaved Transition Systems, which properly contains WSTS, and for which coverability is still decidable by a forward algorithm. We then recall the completion of WSTS which leads to defining a conceptual Karp-Miller procedure that terminates in more cases than the generalized Karp-Miller procedure on extensions of Petri nets.} }

@inproceedings{ABDL-rp16, address = {Aalborg, Denmark}, month = sep, year = 2016, volume = {9899}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Larsen, Kim G. and Srba, Ji{\v{r}}{\'\i}}, acronym = {{RP}'16}, booktitle = {{P}roceedings of the 10th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'16)}, author = {Alechina, Natasha and Bulling, Nils and Demri, St{\'e}phane and Logan, Brian}, title = {On the Complexity of Resource-Bounded Logics}, pages = {36-50}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/ABDL-rp16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/ABDL-rp16.pdf}, doi = {10.1007/978-3-319-45994-3_3}, abstract = {We revisit decidability results for resource-bounded logics and use decision problems on VASS to establish complexity characterisation of (decidable) model-checking problems. We show that the model-checking problem for the logic RB\(\pm\)ATL is 2EXPTIME-complete by using recent results on alternating VASS. Moreover, we establish that the model-checking problem for RBTL is EXPSPACE-complete and that the problem is decidable and of the same complexity for RBTL\textsuperscript{*}, proving a new decidability result as a by-product of the approach. We establish that the model-checking problem for RB\(\pm\)ATL\textsuperscript{*}, the extension of RB\(\pm\)ATL with arbitrary path formulae is decidable by a reduction into parity games. We are also able to synthesise values for resource parameters. Hence, the paper establishes formal correspondences between model-checking problems and decision problems on alternating VASS, paving the way to more applications.} }

@inproceedings{KS-csl16, address = {Marseille, France}, month = sep, year = 2016, volume = {62}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Regnier, Laurent and Talbot, Jean-Marc}, acronym = {{CSL}'16}, booktitle = {{P}roceedings of the 25th {A}nnual {EACSL} {C}onference on {C}omputer {S}cience {L}ogic ({CSL}'16)}, author = {Prateek Karandikar and Schnoebelen, {\relax Ph}ilippe}, title = {The height of piecewise-testable languages with applications in logical complexity}, pages = {37:1-37:22}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-csl16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/KS-csl16.pdf}, doi = {10.4230/LIPIcs.CSL.2016.37}, abstract = {The height of a piecewise-testable language~\(L\) is the maximum length of the words needed to define~\(L\) by excluding and requiring given subwords. The height of~\(L\) is an important descriptive complexity measure that has not yet been investigated in a systematic way. This paper develops a series of new techniques for bounding the height of finite languages and of languages obtained by taking closures by subwords, superwords and related operations.\par As an application of these results, we show that \({\textsf{FO}}^2(A^*,\sqsubseteq)\), the two-variable fragment of the first-order logic of sequences with the subword ordering, can only express piecewise-testable properties and has elementary complexity.} }

@inproceedings{GGL-csl16, address = {Marseille, France}, month = sep, year = 2016, volume = {62}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Regnier, Laurent and Talbot, Jean-Marc}, acronym = {{CSL}'16}, booktitle = {{P}roceedings of the 25th {A}nnual {EACSL} {C}onference on {C}omputer {S}cience {L}ogic ({CSL}'16)}, author = {Ganardi, Moses and G{\"o}ller, Stefan and Lohrey, Markus}, title = {On the Parallel Complexity of Bisimulation over Finite Systems}, pages = {12:1-12:17}, doi = {10.4230/LIPIcs.CSL.2016.12}, abstract = {In this paper the computational complexity of the (bi)simulation problem over restricted graph classes is studied. For trees given as pointer structures or terms the (bi)simulation problem is complete for logarithmic space or NC\(^1\), respectively. This solves an open problem from Balc{\'a}zar, Gabarr{\'o}, and S{\'a}ntha. We also show that the simulation problem is P-complete even for graphs of bounded path-width.} }

@article{DFP-lmcs16, journal = {Logical Methods in Computer Science}, author = {Demri, St{\'e}phane and Figueira, Diego and Praveen, M}, title = {Reasoning about Data Repetitions with Counter Systems}, year = 2016, volume = {12}, number = {3}, month = aug, pages = {1:1-1:55}, url = {http://arxiv.org/abs/1604.02887}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DFP-lmcs16.pdf}, doi = {10.2168/LMCS-12(3:1)2016}, abstract = {We study linear-time temporal logics interpreted over data words with multiple attributes. We restrict the atomic formulas to equalities of attribute values in successive positions and to repetitions of attribute values in the future or past. We demonstrate correspondences between satisfiability problems for logics and reachability-like decision problems for counter systems. We show that allowing\slash disallowing atomic formulas expressing repetitions of values in the past corresponds to the reachability\slash coverability problem in Petri nets. This gives us 2EXPSPACE upper bounds for several satisfiability problems. We prove matching lower bounds by reduction from a reachability problem for a newly introduced class of counter systems. This new class is a succinct version of vector addition systems with states in which counters are accessed via pointers, apotentially useful feature in other contexts. We strengthen further the correspondences between data logics and counter systems by characterizing the complexity of fragments, extensions and variants of the logic. For instance, we precisely characterize the relationship between the number of attributes allowed in the logic and the number of counters needed in the counter system.} }

@inproceedings{CH-icalp16, address = {Rome, Italy}, month = jul, year = 2016, volume = {55}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Chatzigiannakis, Ioannis and Mitzenmacher, Michael and Rabani, Yuval and Sangiorgi, Davide}, acronym = {{ICALP}'16}, booktitle = {{P}roceedings of the 43rd {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'16)}, author = {Dmitry Chistikov and Christoph Haase}, title = {The Taming of the Semi-Linear Set}, pages = {128:1-128:14}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CH-icalp16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CH-icalp16.pdf}, doi = {10.4230/LIPIcs.ICALP.2016.128}, abstract = {Semi-linear sets, which are finitely generated subsets of the monoid \((\mathbb{Z}^d, +)\), have numerous applications in theoretical computer science. Although semi-linear sets are usually given implicitly, by formulas in Presburger arithmetic or by other means, the effect of Boolean operations on semi-linear sets in terms of the size of generators has primarily been studied for explicit representations. In this paper, we develop a framework suitable for implicitly presented semi-linear sets, in which the size of a semi-linear set is characterized by its norm---the maximal magnitude of a generator.\par We put together a {"}toolbox{"} of operations and decompositions for semi-linear sets which give bounds in terms of the norm (as opposed to just the bit-size of the description), a unified presentation, and simplified proofs. This toolbox, in particular, provides exponentially better bounds for the complement and set-theoretic difference. We also obtain bounds on unambiguous decompositions and, as an application of the toolbox, settle the complexity of the equivalence problem for exponent-sensitive commutative grammars.} }

@inproceedings{Zetzche-icalp16, address = {Rome, Italy}, month = jul, year = 2016, volume = {55}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Chatzigiannakis, Ioannis and Mitzenmacher, Michael and Rabani, Yuval and Sangiorgi, Davide}, acronym = {{ICALP}'16}, booktitle = {{P}roceedings of the 43rd {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'16)}, author = {Georg Zetzsche}, title = {The complexity of downward closure comparisons}, pages = {123:1-123:14}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/Zetzche-icalp16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/Zetzche-icalp16.pdf}, doi = {10.4230/LIPIcs.ICALP.2016.123}, abstract = {The downward closure of a language is the set of all (not necessarily contiguous) subwords of its members. It is well-known that the downward closure of every language is regular. Moreover, recent results show that downward closures are computable for quite powerful system models.\par One advantage of abstracting a language by its downward closure is that then, equivalence and inclusion become decidable. In~this work, we study the complexity of these two problems. More precisely, we consider the following decision problems: Given languages~\(K\) and~\(L\) from classes~\(\mathcal{C}\) and~\(\mathcal{D}\), respectively, does the downward closure of~\(K\) include (equal) that of~\(L\)?\par These problems are investigated for finite automata, one-counter automata, context-free grammars, and reversal-bounded counter automata. For each combination, we prove a completeness result either for fixed or for arbitrary alphabets. Moreover, for Petri net languages, we show that both problems are Ackermann-hard and for higher-order pushdown automata of order~\(k\), we prove hardness for complements of nondeterministic \(k\)-fold exponential time.} }

@inproceedings{GLS-icalp16, address = {Rome, Italy}, month = jul, year = 2016, volume = {55}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Chatzigiannakis, Ioannis and Mitzenmacher, Michael and Rabani, Yuval and Sangiorgi, Davide}, acronym = {{ICALP}'16}, booktitle = {{P}roceedings of the 43rd {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'16)}, author = {Goubault{-}Larrecq, Jean and Schmitz, Sylvain}, title = {Deciding Piecewise Testable Separability for Regular Tree Languages}, pages = {97:1-97:15}, url = {https://hal.inria.fr/hal-01276119/}, optpdf = {http://www.lsv.fr/Publis/PAPERS/PDF/GLS-icalp16.pdf}, doi = {10.4230/LIPIcs.ICALP.2016.97}, abstract = {The piecewise testable separability problem asks, given two input languages, whether there exists a piecewise testable language that contains the first input language and is disjoint from the second. We prove a general characterisation of piecewise testable separability on languages in a well-quasi-order, in terms of ideals of the ordering. This subsumes the known characterisations in the case of finite words. In the case of finite ranked trees ordered by homeomorphic embedding, we show using effective representations for tree ideals that it entails the decidability of piecewise testable separability when the input languages are regular. A~final byproduct is a new proof of the decidability of whether an input regular language of ranked trees is piecewise testable, which was first shown in the unranked case by Boja{\'n}czyk, Segoufin, and Straubing (Log.~Meth. in Comput.~Sci.,~8(3:26), 2012).} }

@inproceedings{GHLT-icalp16, address = {Rome, Italy}, month = jul, year = 2016, volume = {55}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Chatzigiannakis, Ioannis and Mitzenmacher, Michael and Rabani, Yuval and Sangiorgi, Davide}, acronym = {{ICALP}'16}, booktitle = {{P}roceedings of the 43rd {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'16)}, author = {Stefan G{\"o}ller and Christoph Haase and Ranko Lazi{\'c} and Patrick Totzke}, title = {A Polynomial-Time Algorithm for Reachability in Branching {VASS} in Dimension One}, pages = {105:1-105:13}, url = {http://arxiv.org/abs/1602.05547}, pfd = {http://www.lsv.fr/Publis/PAPERS/PDF/GHLT-icalp16.pdf}, doi = {10.4230/LIPIcs.ICALP.2016.105}, abstract = {Branching VASS (BVASS) generalise vector addition systems with states by allowing for special branching transitions that can non-deterministically distribute a counter value between two control states. A~run of a BVASS consequently becomes a tree, and reachability is to decide whether a given configuration is the root of a reachability tree. This paper shows P-completeness of reachability in BVASS in dimension one, the first decidability result for reachability in a subclass of BVASS known so~far. Moreover, we~show that coverability and boundedness in BVASS in dimension one are P-complete as~well.} }

@inproceedings{LS-lics16, address = {New York City, USA}, month = jul, year = 2016, publisher = {ACM Press}, editor = {Grohe, Martin and Koskinen, Eric and Shankar, Natarajan}, acronym = {{LICS}'16}, booktitle = {{P}roceedings of the 31st {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'16)}, author = {Ranko Lazi{\'c} and Sylvain Schmitz}, title = {The Complexity of Coverability in {{\(\nu\)}}-{P}etri Nets}, pages = {467-476}, url = {https://hal.inria.fr/hal-01265302}, doi = {10.1145/2933575.2933593}, abstract = {We show that the coverability problem in nu-Petri nets is complete for `double Ackermann' time, thus closing an open complexity gap between an Ackermann lower bound and a hyper-Ackermann upper bound. The coverability problem captures the verification of safety properties in this nominal extension of Petri nets with name management and fresh name creation. Our completeness result establishes nu-Petri nets as a model of intermediate power among the formalisms of nets enriched with data, and relies on new algorithmic insights brought by the use of well-quasi-order ideals.} }

@inproceedings{CG-lics16, address = {New York City, USA}, month = jul, year = 2016, publisher = {ACM Press}, editor = {Grohe, Martin and Koskinen, Eric and Shankar, Natarajan}, acronym = {{LICS}'16}, booktitle = {{P}roceedings of the 31st {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'16)}, author = {{\relax Th}omas Colcombet and Stefan G{\"o}ller}, title = {Games with bound guess actions}, pages = {257-266}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/CG-lics16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CG-lics16.pdf}, doi = {10.1145/2933575.2934502}, abstract = {We introduce games with (bound) guess actions. These are games in which the players may be asked along the play to provide num- bers that need to satisfy some bounding constraints. These are nat- ural extensions of domination games occurring in the regular cost function theory. In this paper we consider more specifically the case where the constraints to be bounded are regular cost functions, and the long term goal is an ?-regular winning condition. We show that such games are decidable on finite arenas.} }

@inproceedings{DOMZ-lics16, address = {New York City, USA}, month = jul, year = 2016, publisher = {ACM Press}, editor = {Grohe, Martin and Koskinen, Eric and Shankar, Natarajan}, acronym = {{LICS}'16}, booktitle = {{P}roceedings of the 31st {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'16)}, author = {D'Osualdo, Emanuele and Roland Meyer and Georg Zetzsche}, title = {First-order logic with reachability for infinite-state systems}, pages = {457-466}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DOMZ-lics16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DOMZ-lics16.pdf}, doi = {10.1145/2933575.2934552}, abstract = {First-order logic with the reachability predicate (FO(R)) is an important means of specification in system analysis. Its decidability status is known for some individual types of infinite-state systems such as pushdown (decidable) and vector addition systems (undecidable). \par This work aims at a general understanding of which types of systems admit decidability. As a unifying model, we employ valence systems over graph monoids, which feature a finite-state control and are parameterized by a monoid to represent their storage mechanism. As special cases, this includes pushdown systems, various types of counter systems (such as vector addition systems) and combinations thereof. Our main result is a complete characterization of those graph monoids where FO(R) is decidable for the resulting transition systems.} }

@inproceedings{ACHKSZ-lics16, address = {New York City, USA}, month = jul, year = 2016, publisher = {ACM Press}, editor = {Grohe, Martin and Koskinen, Eric and Shankar, Natarajan}, acronym = {{LICS}'16}, booktitle = {{P}roceedings of the 31st {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'16)}, author = {Atig, Mohamed Faouzi and Dmitry Chistikov and Piotr Hofman and Kumar, K. Narayan and Prakash Saivasan and Georg Zetzsche}, title = {Complexity of regular abstractions of one-counter languages}, pages = {207-216}, url = {http://arxiv.org/abs/1602.03419}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/ACHKSZ-lics16.pdf}, doi = {10.1145/2933575.2934561}, abstract = {We study the computational and descriptional complexity of the following transformation: Given a one-counter automaton~(OCA)~\(A\), construct a nondeterministic finite automaton~(NFA)~\(B\) that recognizes an abstraction of the language~\(L(A)\): its~(1)~downward closure, (2)~upward closure, or (3)~Parikh image. For the Parikh image over a fixed alphabet and for the upward and downward closures, we find polynomial-time algorithms that compute such an NFA. For the Parikh image with the alphabet as part of the input, we find a quasi-polynomial time algorithm and prove a completeness result: we construct a sequence of OCA that admits a polynomial-time algorithm iff there is one for all OCA. For all three abstractions, it was previously unknown if appropriate NFA of sub-exponential size exist.} }

@comment{{B-arxiv16, author = Bollig, Benedikt, affiliation = aff-LSVmexico, title = One-Counter Automata with Counter Visibility, institution = Computing Research Repository, number = 1602.05940, month = feb, nmonth = 2, year = 2016, type = RR, axeLSV = mexico, NOcontrat = "", url = http://arxiv.org/abs/1602.05940, PDF = "http://www.lsv.fr/Publis/PAPERS/PDF/B-arxiv16.pdf", lsvdate-new = 20160222, lsvdate-upd = 20160222, lsvdate-pub = 20160222, lsv-category = "rapl", wwwpublic = "public and ccsb", note = 18~pages, abstract = "In a one-counter automaton (OCA), one can read a letter from some finite alphabet, increment and decrement the counter by one, or test it for zero. It is well-known that universality and language inclusion for OCAs are undecidable. We consider here OCAs with counter visibility: Whenever the automaton produces a letter, it outputs the current counter value along with~it. Hence, its language is now a set of words over an infinite alphabet. We show that universality and inclusion for that model are in PSPACE, thus no harder than the corresponding problems for finite automata, which can actually be considered as a special case. In fact, we show that OCAs with counter visibility are effectively determinizable and closed under all boolean operations. As~a~strict generalization, we subsequently extend our model by registers. The general nonemptiness problem being undecidable, we impose a bound on the number of register comparisons and show that the corresponding nonemptiness problem is NP-complete.", }}

@techreport{CHH-arxiv16, author = {Chistikov, Dmitry and Haase, Christoph and Halfon, Simon}, title = {Context-Free Commutative Grammars with Integer Counters and Resets}, institution = {Computing Research Repository}, number = {1511-04893}, year = {2015}, month = nov, type = {Research Report}, url = {http://arxiv.org/abs/1511.04893}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CHH-arxiv16.pdf}, note = {31~pages}, abstract = {We study the computational complexity of reachability, coverability and inclusion for extensions of context-free commutative grammars with integer counters and reset operations on them. Those grammars can alternatively be viewed as an extension of communication-free Petri nets. Our main results are that reachability and coverability are inter-reducible and both NP-complete. In particular, this class of commutative grammars enjoys semi-linear reachability sets. We also show that the inclusion problem is, in general, coNEXP-complete and already \(\Pi^{P}_{2}\)-complete for grammars with only one non-terminal symbol. Showing the lower bound for the latter result requires us to develop a novel \(\Pi^{P}_{2}\)-complete variant of the classic subset sum problem.} }

@article{DGLM-tocs16, publisher = {Springer}, journal = {Theory of Computing Systems}, author = {Demri, St{\'e}phane and Galmiche, Didier and Larchey-Wendling, Dominique and Mery, Daniel}, title = {Separation Logic with One Quantified Variable}, year = 2017, volume = {61}, number = {2}, pages = {371-461}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DGLM-tocs16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DGLM-tocs16.pdf}, doi = {10.1007/s00224-016-9713-1}, abstract = {We investigate first-order separation logic with one record field restricted to a unique quantified variable (1SL1). Undecidability is known when the number of quantified variables is unbounded and the satisfiability problem is pspace-complete for the propositional fragment. We show that the satisfiability problem for 1SL1 is pspace-complete and we characterize its expressive power by showing that every formula is equivalent to a Boolean combination of atomic properties. This contributes to our understanding of fragments of first-order separation logic that can specify properties about the memory heap of programs with singly-linked lists. All the fragments we consider contain the magic wand operator and first-order quantification over a single variable.} }

@inproceedings{LS-stacs16, address = {Orl{\'e}ans, France}, month = feb, year = 2016, volume = {47}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Ollinger, Nicolas and Vollmer, Heribert}, acronym = {{STACS}'16}, booktitle = {{P}roceedings of the 33rd {A}nnual {S}ymposium on {T}heoretical {A}spects of {C}omputer {S}cience ({STACS}'16)}, author = {Leroux, J{\'e}r{\^o}me and Schmitz, Sylvain}, title = {Ideal Decompositions for Vector Addition Systems}, pages = {1:1-1:13}, url = {http://drops.dagstuhl.de/opus/volltexte/2016/5702}, doi = {10.4230/LIPIcs.STACS.2016.1}, abstract = {Vector addition systems, or equivalently Petri nets, are one of the most popular formal models for the representation and the analysis of parallel processes. Many problems for vector addition systems are known to be decidable thanks to the theory of well-structured transition systems. Indeed, vector addition systems with configurations equipped with the classical point-wise ordering are well-structured transition systems. Based on this observation, problems like coverability or termination can be proven decidable.\par However, the theory of well-structured transition systems does not explain the decidability of the reachability problem. In this presentation, we show that runs of vector addition systems can also be equipped with a well quasi-order. This observation provides a unified understanding of the data structures involved in solving many problems for vector addition systems, including the central reachability problem.} }

@article{siglog16-Schmitz, publisher = {ACM Press}, journal = {SIGLOG News}, author = {Schmitz, Sylvain}, title = {Automata column: The~complexity of reachability in vector addition systems}, volume = 3, number = 1, pages = {3-21}, year = 2016, month = jan, url = {https://hal.inria.fr/hal-01275972}, doi = {10.1145/2893582.2893585}, annote = {Invited column}, abstract = {The program of the 30th Symposium on Logic in Computer Science held in 2015 in Kyoto included two contributions on the computational complexity of the reachability problem for vector addition systems: Blondin, Finkel, G{\"o}ller, Haase, and McKenzie~[2015] attacked the problem by providing the first tight complexity bounds in the case of dimension-2 systems with states, while Leroux and Schmitz~[2015] proved the first complexity upper bound in the general case. The purpose of this column is to present the main ideas behind these two results, and more generally survey the current state of affairs.} }

@article{CFS-tcs16, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Chambart, Pierre and Finkel, Alain and Schmitz, Sylvain}, title = {Forward Analysis and Model Checking for Trace Bounded~{WSTS}}, year = 2016, volume = {637}, pages = {1-29}, month = jul, url = {http://arxiv.org/abs/1004.2802}, doi = {10.1016/j.tcs.2016.04.020}, abstract = {We investigate a subclass of well-structured transition systems~(WSTS), the bounded---in the sense of Ginsburg and Spanier (Trans.~AMS, 1964)---complete deterministic ones, which we claim provide an adequate basis for the study of forward analyses as developed by Finkel and Goubault-Larrecq (ICALP~2009). Indeed, we prove that, unlike other conditions considered previously for the termination of forward analysis, boundedness is decidable. Boundedness turns out to be a valuable restriction for WSTS verification, as we show that it further allows to decide all {{\(\omega\)}}-regular properties on the set of infinite traces of the system.} }

@article{toct-Schmitz13, publisher = {ACM Press}, journal = {ACM Transactions on Computation Theory}, author = {Schmitz, Sylvain}, title = {Complexity Hierarchies Beyond {E}lementary}, volume = {8}, number = {1:3}, nopages = {}, year = 2016, month = feb, url = {http://arxiv.org/abs/1312.5686}, doi = {10.1145/2858784}, abstract = {We introduce a hierarchy of fast-growing complexity classes and show its suitability for completeness statements of many non elementary problems. This hierarchy allows the classification of many decision problems with a non-elementary complexity, which occur naturally in logic, combinatorics, formal languages, verification, etc., with complexities ranging from simple towers of exponentials to Ackermannian and beyond.} }

@inproceedings{CCHPW-fossacs16, address = {Eindhoven, The~Netherlands}, month = apr, year = 2016, volume = {9634}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Jacobs, Bart and L{\"o}ding, Christof}, acronym = {{FoSSaCS}'16}, booktitle = {{P}roceedings of the 19th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'16)}, author = {Chistikov, Dmitry and Czerwi{\'n}ski, Wojciech and Hofman, Piotr and Pilipczuk, Micha{\l} and Wehar, Michael}, title = {Shortest paths in one-counter systems}, pages = {462-478}, url = {http://arxiv.org/abs/1510.05460}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/CCHPW-fossacs16.pdf}, doi = {10.1007/978-3-662-49630-5_27}, abstract = {We show that any one-counter automaton with \(n\) states, if its language is non-empty, accepts some word of length at most~\(O(n^2)\). This closes the gap between the previously known upper bound of~\(O(n^3)\) and lower bound of~\(\Omega(n^2)\). More generally, we prove a tight upper bound on the length of shortest paths between arbitrary configurations in one-counter transition systems. Weaker bounds have previously appeared in the literature, and our result offers an improvement.} }

@inproceedings{HLLLST-fossacs16, address = {Eindhoven, The~Netherlands}, month = apr, year = 2016, volume = {9634}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Jacobs, Bart and L{\"o}ding, Christof}, acronym = {{FoSSaCS}'16}, booktitle = {{P}roceedings of the 19th {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'16)}, author = {Hofman, Piotr and Lasota, S{\l}awomir and Lazi{\'c}, Ranko and Leroux, J{\'e}r{\^o}me and Schmitz, Sylvain and Totzke, Patrick}, title = {Coverability Trees for {P}etri Nets with Unordered Data}, pages = {445-461}, url = {https://hal.inria.fr/hal-01252674}, doi = {10.1007/978-3-662-49630-5_26}, abstract = {We study an extension of classical Petri nets where tokens carry values from a countable data domain, that can be tested for equality upon firing transitions. These Unordered Data Petri Nets (UDPN) are well-structured and therefore allow generic decision procedures for several verification problems including coverability and boundedness. We show how to construct a finite representation of the coverability set in terms of its ideal decomposition. This not only provides an alternative method to decide coverability and boundedness, but is also an important step towards deciding the reachability problem. This also allows to answer more precise questions about the reachability set, for instance whether there is a bound on the number of tokens on a given place (place boundedness), or if such a bound exists for the number of different data values carried by tokens (place width boundedness). We provide matching Hyper-Ackermann bounds on the size of cover-ability trees and on the running time of the induced decision procedures.} }

@inproceedings{tacas16-BFHH, address = {Eindhoven, The Netherlands}, month = apr, year = 2016, volume = {9636}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Chechik, Marsha and Raskin, Jean-Fran{\c{c}}ois}, acronym = {{TACAS}'16}, booktitle = {{P}roceedings of the 22th {I}nternational {C}onference on {T}ools and {A}lgorithms for {C}onstruction and {A}nalysis of {S}ystems ({TACAS}'16)}, author = {Blondin, Michael and Finkel, Alain and Haase, Christoph and Haddad, Serge}, title = {Approaching the Coverability Problem Continuously}, pages = {480-496}, url = {http://arxiv.org/abs/1510.05724}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/arxiv15-BFHH.pdf}, doi = {10.1007/978-3-662-49674-9_28}, abstract = {The coverability problem for Petri nets plays a central role in the verification of concurrent shared-memory programs. However, its high EXPSPACE-complete complexity poses a challenge when encountered in real-world instances. In this paper, we develop a new approach to this problem which is primarily based on applying forward coverability in continuous Petri nets as a pruning criterion inside a backward coverability framework. A cornerstone of our approach is the efficient encoding of a recently developed polynomial-time algorithm for reachability in continuous Petri nets into SMT. We demonstrate the effectiveness of our approach on standard benchmarks from the literature, which shows that our approach decides significantly more instances than any existing tool and is in addition often much faster, in particular on large instances.} }

@inproceedings{HH-stacs16, address = {Orl{\'e}ans, France}, month = feb, year = 2016, volume = {47}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Ollinger, Nicolas and Vollmer, Heribert}, acronym = {{STACS}'16}, booktitle = {{P}roceedings of the 33rd {A}nnual {S}ymposium on {T}heoretical {A}spects of {C}omputer {S}cience ({STACS}'16)}, author = {Haase, Christoph and Hofman, Piotr}, title = {Tightening the Complexity of Equivalence Problems for Commutative Grammars}, pages = {41:1-14}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/HH-stacs16.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HH-stacs16.pdf}, doi = {10.4230/LIPIcs.STACS.2016.41}, abstract = {Given two finite-state automata, are the Parikh images of the languages they generate equivalent? This problem was shown decidable in coNEXP by Huynh in 1985 within the more general setting of context-free commutative grammars. Huynh conjectured that a~\(\Pi_{2}^{P}\) upper bound might be possible, and Kopczy{\'n}ski and To established in 2010 such an upper bound when the size of the alphabet is fixed. The contribution of this paper is to show that the language equivalence problem for regular and context-free commutative grammars is actually coNEXP-complete. In addition, our lower bound immediately yields further coNEXP-completeness results for equivalence problems for regular commutative expressions, reversal-bounded counter automata and communication-free Petri nets. Finally, we improve both lower and upper bounds for language equivalence for exponent-sensitive commutative grammars.} }

@article{DD-tocl15b, publisher = {ACM Press}, journal = {ACM Transactions on Computational Logic}, author = {Demri, St{\'e}phane and Deters, Morgan}, title = {Expressive Completeness of Separation Logic With Two Variables and No Separating Conjunction}, volume = {17}, number = {2}, pages = {12:1-12:44}, month = mar, year = 2016, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-tocl15b.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DD-tocl15b.pdf}, doi = {10.1145/2835490}, abstract = {Separation logic is used as an assertion language for Hoare-style proof systems about programs with pointers, and there is an ongoing quest for understanding its complexity and expressive power. Herein, we show that first-order separation logic with one record field restricted to two variables and the separating implication (no~separating conjunction) is as expressive as weak second-order logic, substantially sharpening a previous result. Capturing weak second-order logic with such a restricted form of separation logic requires substantial updates to known proof techniques. We develop these, and as a by-product identify the smallest fragment of separation logic known to be undecidable: first-order separation logic with one record field, two variables, and no separating conjunction. Because we forbid ourselves the use of many syntactic resources, this underscores even further the power of separating implication on concrete heaps.} }

@article{HOW-fi15, publisher = {{IOS} Press}, journal = {Fundamenta Informaticae}, author = {Haase, Christoph and Ouaknine, Jo{\"e}l and Worrell, James}, title = {Relating Reachability Problems in Timed and Counter Automata}, volume = {143}, number = {3-4}, pages = {317-338}, year = 2016, month = jan, url = {http://www.lsv.fr/Publis/PAPERS/PDF/HOW-fi15.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/HOW-fi15.pdf}, doi = {10.3233/FI-2016-1316}, abstract = {We establish a relationship between reachability problems in timed automata and space-bounded counter automata. We show that reachability in timed automata with three or more clocks is logarithmic-space inter-reducible with reachability in space-bounded counter automata with two counters. We moreover show the logarithmic-space equivalence of reachability in two-clock timed automata and space-bounded one-counter automata. This last reduction has recently been employed by Fearnley and Jurdzi{\'n}ski to settle the computational complexity of reachability in two-clock timed automata.} }

@article{CMRZZ-dmtcs2017, journal = {Discrete Mathematics \& Theoretical Computer Science}, author = {Czerwi{\'{n}}ski, Wojciech and Martens, Wim and van Rooijen, Lorijn and Zeitoun, Marc and Zetzsche, Georg}, title = {A Characterization for Decidable Separability by Piecewise Testable Languages}, volume = {19}, number = {4}, year = {2017}, month = dec, nopages = {}, doi = {10.23638/DMTCS-19-4-1}, url = {https://dmtcs.episciences.org/4131}, pdf = {https://arxiv.org/pdf/1410.1042.pdf} }

@article{HKZ-sf2017, publisher = {Springer}, journal = {Semigroup Forum}, author = {Huschenbett, Martin and Kuske, Dietrich and Zetzsche, Georg}, title = {The Monoid of Queue Actions}, volume = {95}, number = {3}, year = {2017}, month = dec, pages = {475-508}, doi = {10.1007/s00233-016-9835-4}, abstract = {We model the behavior of a fifo-queue as a monoid of transformations that are induced by sequences of writing and reading. We describe this monoid by means of a confluent and terminating semi-Thue system and study some of its basic algebraic properties such as conjugacy. Moreover, we show that while several properties concerning its rational subsets are undecidable, their uniform membership problem is NL-complete. Furthermore, we present an algebraic characterization of this monoid's recognizable subsets. Finally, we prove that it is not Thurston-automatic.} }

@article{ZKL-tocs17, publisher = {Springer}, journal = {Theory of Computing Systems}, author = {Zetzsche, Georg and Kuske, Dietrich and Lohrey, Markus}, title = {On {Boolean} closed full trios and rational {Kripke} frames}, volume = {60}, number = {3}, year = {2017}, month = apr, pages = {438-472}, doi = {10.1007/s00224-016-9694-0} }

@mastersthesis{m2-riesner, author = {Riesner, M{\'e}lissa}, title = {Regularity of deterministic pushdown automata}, school = {{M}aster {P}arisien de {R}echerche en {I}nformatique, Paris, France}, type = {Rapport de {M}aster}, year = {2017}, month = aug }

@article{BFM-lmcs17, journal = {Logical Methods in Computer Science}, author = {Blondin, Michael and Finkel, Alain and McKenzie, Pierre}, title = {Well Behaved Transition Systems}, volume = {13}, number = {3}, year = {2017}, month = sep, pages = {1-19}, doi = {10.23638/LMCS-13(3:24)2017}, url = {https://doi.org/10.23638/LMCS-13(3:24)2017} }

@phdthesis{schmitz-hdr2017, author = {Schmitz, Sylvain}, title = {Algorithmic Complexity of Well-Quasi-Orders}, school = {{\'E}cole Normale Sup{\'e}rieure Paris-Saclay, France}, type = {M{\'e}moire d'habilitation}, year = 2017, month = nov, url = {http://tel.archives-ouvertes.fr/tel-01663266} }

@inproceedings{GKLZ-stacs18, address = {Caen, France}, month = feb, volume = {96}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Niedermeier, Rolf and Vall{\'e}e, Brigitte}, acronym = {{STACS}'18}, booktitle = {{P}roceedings of the 35th {A}nnual {S}ymposium on {T}heoretical {A}spects of {C}omputer {S}cience ({STACS}'18)}, author = {Ganardi, Moses and K{\"o}nig, Daniel and Lohrey, Markus and Zetzsche, Georg}, title = {Knapsack problems for wreath products}, pages = {32:1-32:13}, year = {2018}, doi = {10.4230/LIPIcs.STACS.2018.32}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2018/8520/pdf/LIPIcs-STACS-2018-32.pdf}, url = {http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=8520} }

@inproceedings{PhS-mfcs17, address = {Aalborg, Denmark}, month = aug, year = 2017, volume = {83}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Larsen, Kim G. and Bodlaender, Hans L. and Raskin, Jean-Fran{\c{c}}ois}, acronym = {{MFCS}'17}, booktitle = {{P}roceedings of the 42nd {I}nternational {S}ymposium on {M}athematical {F}oundations of {C}omputer {S}cience ({MFCS}'17)}, author = {Schnoebelen, {\relax Ph}ilippe}, title = {Ideal-Based Algorithms for the Symbolic Verification of Well-Structured Systems (Invited Talk)}, pages = {85:1-85:4}, url = {http://drops.dagstuhl.de/opus/volltexte/2017/8139/}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2017/8139/pdf/LIPIcs-MFCS-2017-85.pdf}, doi = {10.4230/LIPIcs.MFCS.2017.85}, abstract = {We explain how the downward-closed subsets of a well-quasi-ordering (\(X,\leq\)) can be represented via the ideals of \(X\) and how this leads to simple and efficient algorithms for the verification of well-structured systems.} }

@incollection{DSS-wqo17, author = {D{\v z}amonja, Mirna and Schmitz, Sylvain and Schnoebelen, {\relax Ph}ilippe}, title = {On ordinal invariants in well quasi orders and finite antichain orders}, booktitle = {Well-quasi orders in computation, logic, language and reasoning}, editor = {Peter Schuster and Monika Seisenberer and Andreas Weiermann}, publisher = {Springer}, series = {Trends in Logic}, url = {https://arxiv.org/abs/1711.00428}, pdf = {https://arxiv.org/pdf/1711.00428}, year = {2019}, optnmonth = {}, abstract = {We investigate the ordinal invariants height, length, and width of well quasi orders (WQO), with particular emphasis on width, an invariant of interest for the larger class of orders with finite antichain condition (FAC). We show that the width in the class of FAC orders is completely determined by the width in the class of WQOs, in the sense that if we know how to calculate the width of any WQO then we have a procedure to calculate the width of any given FAC order. We show how the width of WQO orders obtained via some classical constructions can sometimes be computed in a compositional way. In particular, this allows proving that every ordinal \(\alpha\) can be obtained as the width of some WQO poset. One of the difficult questions is to give a complete formula for the width of Cartesian products of WQOs. Even the width of the product of two ordinals is only known through a complex recursive formula. Although we have not given a complete answer to this question we have advanced the state of knowledge by considering some more complex special cases and in particular by calculating the width of certain products containing three factors. In the course of writing the paper we have discovered that some of the relevant literature was written on cross-purposes and some of the notions rediscovered several times. Therefore we also use the occasion to give a unified presentation of the known results.}, note = {To appear} }

@article{BFM-ic17, publisher = {Elsevier Science Publishers}, journal = {Information and Computation}, author = {Blondin, Michael and Finkel, Alain and McKenzie, Pierre}, title = {Handling Infinitely Branching Well-structured Transition Systems}, volume = {258}, year = {2018}, pages = {28--49}, doi = {10.1016/j.ic.2017.11.001} }

@article{DDS-tcs17, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Demri, St{\'e}phane and Dhar, Amit and Sangnier, Arnaud}, title = {Equivalence Between Model-Checking Flat Counter Systems and Presburger Arithmetic}, volume = {735}, optnumber = {}, year = {2017}, pages = {2-23}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DDS-tcs17.pdf} }

@inproceedings{BLL-rp17, address = {London, UK}, month = sep, year = 2017, volume = {10506}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Matthew Hague and Igor Potapov}, acronym = {{RP}'17}, booktitle = {{P}roceedings of the 11th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'17)}, author = {Florian Bruse and Martin Lange and {\'E}tienne Lozes}, title = {Space-Efficient Fragments of Higher-Order Fixpoint Logic}, pages = {26-41}, url = {https://doi.org/10.1007/978-3-319-67089-8_3}, doi = {10.1007/978-3-319-67089-8_3}, abstract = {Higher-Order Fixpoint Logic (HFL) is a modal specification language whose expressive power reaches far beyond that of Monadic Second-Order Logic, achieved through an incorporation of a typed \(\lambda\)-calculus into the modal \(\mu\)-calculus. Its model checking problem on finite transition systems is decidable, albeit of high complexity, namely \(k\)-EXPTIME-complete for formulas that use functions of type order at most \(k>0\). In this paper we present a fragment with a presumably easier model checking problem. We show that so-called tail-recursive formulas of type order \(k\) can be model checked in \((k-1)\)-EXPSPACE, and also give matching lower bounds. This yields generic results for the complexity of bisimulation-invariant non-regular properties, as these can typically be defined in HFL.} }

@inproceedings{BFG-fsttcs17, address = {Kanpur, India}, month = dec, year = 2017, volume = {93}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Satya Lokam and R. Ramanujam}, acronym = {{FSTTCS}'17}, booktitle = {{P}roceedings of the 37th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'17)}, author = {Michael Blondin and Alain Finkel and Jean Goubault{-}Larrecq}, title = {Forward Analysis for {WSTS}, {Part III}: {Karp-Miller} Trees}, pages = {16:1-16:15}, url = {https://hal.archives-ouvertes.fr/hal-01736704/}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2018/8403/pdf/LIPIcs-FSTTCS-2017-16.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2017.16}, abstract = {This paper is a sequel of ''Forward Analysis for WSTS, Part I: Completions'' [STACS 2009, LZI Intl. Proc. in Informatics 3, 433-444] and ''Forward Analysis for WSTS, Part II: Complete WSTS'' [Logical Methods in Computer Science 8(3), 2012]. In these two papers, we provided a framework to conduct forward reachability analyses of WSTS, using finite representations of downwards-closed sets. We further develop this framework to obtain a generic Karp-Miller algorithm for the new class of very-WSTS. This allows us to show that coverability sets of very-WSTS can be computed as their finite ideal decompositions. Under natural assumptions on positive sequences, we also show that LTL model checking for very-WSTS is decidable. The termination of our procedure rests on a new notion of acceleration levels, which we study. We characterize those domains that allow for only finitely many accelerations, based on ordinal ranks.} }

@inproceedings{DLL-fsttcs17, address = {Kanpur, India}, month = dec, year = 2017, volume = {93}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Satya Lokam and R. Ramanujam}, acronym = {{FSTTCS}'17}, booktitle = {{P}roceedings of the 37th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'17)}, author = {St{\'e}phane Demri and {\'E}tienne Lozes and Denis Lugiez}, title = {On Symbolic Heaps Modulo Permission Theories}, pages = {25:1-25:14}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DLL-fsttcs17.pdf}, url = {https://doi.org/10.4230/LIPIcs.FSTTCS.2017.25}, doi = {10.4230/LIPIcs.FSTTCS.2017.25} }

@article{BGH-fmsd17, publisher = {Springer}, journal = {Formal Methods in System Design}, author = {Bollig, Benedikt and Grindei, Manuela-Lidia and Habermehl, Peter}, title = {Realizability of Concurrent Recursive Programs}, year = {2018}, abstract = {We study the realizability problem for concurrent recursive programs: Given a distributed system architecture and a sequential specification over words, find a distributed automata implementation that is equivalent to the specification. This problem is well-studied as far as finite-state processes are concerned, and it has a solution in terms of Zielonka's Theorem. We lift Zielonka's Theorem to the case where processes are recursive and modeled as visibly pushdown (or, equivalently, nested-word) automata. However, contrarily to the finite-state case, it is undecidable whether a specification is realizable or not. Therefore, we also consider suitable underapproximation techniques from the literature developed for multi-pushdown systems, and we show that they lead to a realizability framework with effective algorithms. }, note = {To appear} }

@article{BFHH-tocl17, publisher = {ACM Press}, journal = {ACM Transactions on Computational Logic}, author = {Blondin, Michael and Finkel, Alain and Haase, Christoph and Haddad, Serge}, title = {The Logical View on Continuous {P}etri Nets}, volume = {18}, number = {3}, year = {2017}, pages = {24:1--24:28}, url = {http://doi.acm.org/10.1145/3105908}, doi = {10.1145/3105908}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/BFHH-tocl17.pdf}, abstract = {Continuous Petri nets are a relaxation of classical discrete Petri nets in which transitions can be fired a fractional number of times, and consequently places may contain a fractional number of tokens. Such continuous Petri nets are an appealing object to study since they over approximate the set of reachable configurations of their discrete counterparts, and their reachability problem is known to be decidable in polynomial time. The starting point of this paper is to show that the reachability relation for continuous Petri nets is definable by a sentence of linear size in the existential theory of the rationals with addition and order. Using this characterization, we obtain decidability and complexity results for a number of classical decision problems for continuous Petri nets. In particular, we settle the open problem about the precise complexity of reachability set inclusion. Finally, we show how continuous Petri nets can be incorporated inside the classical backward coverability algorithm for discrete Petri nets as a pruning heuristic in order to tackle the symbolic state explosion problem. The cornerstone of the approach we present is that our logical characterization enables us to leverage the power of modern SMT-solvers in order to yield a highly performant and robust decision procedure for coverability in Petri nets. We demonstrate the applicability of our approach on a set of standard benchmarks from the literature.} }

@inproceedings{FL-icalp17, address = {Warsaw, Poland}, month = jul, volume = {80}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Chatzigiannakis, Ioannis and Indyk, Piotr and Muscholl, Anca and Kuhn, Fabian}, acronym = {{ICALP}'17}, booktitle = {{P}roceedings of the 44th {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'17)}, author = {Finkel, Alain and Lozes, {\'E}tienne}, title = {Synchronizability of Communicating Finite State Machines is not Decidable}, pages = {122:1-122:14}, year = {2017}, doi = {10.4230/LIPIcs.ICALP.2017.122}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2017/7402/pdf/LIPIcs-ICALP-2017-122.pdf}, url = {http://drops.dagstuhl.de/opus/volltexte/2017/7402}, abstract = {A system of communicating finite state machines is synchronizable if its send trace semantics, i.e. the set of sequences of sendings it can perform, is the same when its communications are FIFO asynchronous and when they are just rendez-vous synchronizations. This property was claimed to be decidable in several conference and journal papers for either mailboxes or peer-to-peer communications, thanks to a form of small model property. In this paper, we show that this small model property does not hold neither for mailbox communications, nor for peer-to-peer communications, therefore the decidability of synchronizability becomes an open question. We close this question for peer-to-peer communications, and we show that synchronizability is actually undecidable. We show that synchronizability is decidable if the topology of communications is an oriented ring. We also show that, in this case, synchronizability implies the absence of unspecified receptions and orphan messages, and the channel-recognizability of the reachability set.} }

@inproceedings{HSZ-lics17, address = {Reykjavik, Iceland}, month = jun, publisher = {{IEEE} Press}, editor = {Ouaknine, Jo{\"e}l}, acronym = {{LICS}'17}, booktitle = {{P}roceedings of the 32nd {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'17)}, author = {Halfon, Simon and Schnoebelen, {\relax Ph}ilippe and Zetzsche, Georg}, title = {Decidability, complexity, and expressiveness of first-order logic over the subword ordering}, pages = {1-12}, year = {2017}, doi = {10.1109/LICS.2017.8005141}, url = {https://arxiv.org/abs/1701.07470}, abstract = {We consider first-order logic over the subword ordering on finite words, where each word is available as a constant. Our first result is that the \(\Sigma_1\) theory is undecidable (already over two letters).\par We investigate the decidability border by considering fragments where all but a certain number of variables are alternation bounded, meaning that the variable must always be quantified over languages with a bounded number of letter alternations. We prove that when at most two variables are not alternation bounded, the \(\Sigma_1\) fragment is decidable, and that it becomes undecidable when three variables are not alternation bounded. Regarding higher quantifier alternation depths, we prove that the \(\Sigma_2\) fragment is undecidable already for one variable without alternation bound and that when all variables are alternation bounded, the entire first-order theory is decidable.} }

@inproceedings{CJLS-lics17, address = {Reykjavik, Iceland}, month = jun, publisher = {{IEEE} Press}, editor = {Ouaknine, Jo{\"e}l}, acronym = {{LICS}'17}, booktitle = {{P}roceedings of the 32nd {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'17)}, author = {Colcombet, {\relax Th}omas and Jurdzi{\'n}ski, Marcin and Lazi{\'c}, Ranko and Schmitz, Sylvain}, title = {Perfect Half Space Games}, pages = {1--11}, year = {2017}, doi = {10.1109/LICS.2017.8005105}, url = {http://arxiv.org/abs/1704.05626}, abstract = {We introduce perfect half space games, in which the goal of Player 2 is to make the sums of encountered multi-dimensional weights diverge in a direction which is consistent with a chosen sequence of perfect half spaces (chosen dynamically by Player 2). We establish that the bounding games of Jurdzinski et al. (ICALP 2015) can be reduced to perfect half space games, which in turn can be translated to the lexicographic energy games of Colcombet and Niwinski, and are positionally determined in a strong sense (Player 2 can play without knowing the current perfect half space). We finally show how perfect half space games and bounding games can be employed to solve multi-dimensional energy parity games in pseudo-polynomial time when both the numbers of energy dimensions and of priorities are fixed, regardless of whether the initial credit is given as part of the input or existentially quantified. This also yields an optimal 2EXP complexity with given initial credit, where the best known upper bound was non-elementary.} }

@inproceedings{BHSS-pn17, address = {Zaragoza, Spain}, month = jun, volume = {10258}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {van der Aalst, Wifred and Best, Eike}, acronym = {{PETRI~NETS}'17}, booktitle = {{P}roceedings of the 38th {I}nternational {C}onference on {A}pplications and {T}heory of {P}etri {N}ets ({PETRI~NETS}'17)}, author = {B{\'e}rard, B{\'e}atrice and Haar, Stefan and Schmitz, Sylvain and Schwoon, Stefan}, title = {The Complexity of Diagnosability and Opacity Verification for {P}etri Nets}, pages = {200-220}, year = {2017}, doi = {10.1007/978-3-319-57861-3_13}, url = {https://hal.inria.fr/hal-01484476}, abstract = {Diagnosability and opacity are two well-studied problems in discrete-event systems. We revisit these two problems with respect to expressiveness and complexity issues. We first relate different notions of diagnosability and opacity. We consider in particular fairness issues and extend the definition of Germanos et al. [ACM TECS, 2015] of weakly fair diagnosability for safe Petri nets to general Petri nets and to opacity questions. Second, we provide a global picture of complexity results for the verification of diagnosability and opacity. We show that diagnosability is NL-complete for finite state systems, PSPACE-complete for safe Petri nets (even with fairness), and EXPSPACE-complete for general Petri nets without fairness, while non diagnosability is inter-reducible with reachability when fault events are not weakly fair. Opacity is ESPACE-complete for safe Petri nets (even with fairness) and undecidable for general Petri nets already without fairness.} }

@article{DKP-jar2017, publisher = {Springer}, journal = {Journal of Automated Reasoning}, author = {Demri, St{\'e}phane and Kapur, Deepak and Weidenbach, Christoph}, editor = {Demri, St{\'e}phane and Kapur, Deepak and Weidenbach, Christoph}, title = {Special Issue of Selected Extended Papers of IJCAR 2014}, url = {http://link.springer.com/journal/10817/58/1/page/1}, volume = {58}, number = {1}, year = {2017} }

@incollection{SD-EORM18, author = {Demri, St{\'e}phane}, title = {Reasoning about reversal-bounded counter machines}, editor = {Goli{\'n}ska-Pilarek, Joanna and Zawidzki, Micha\l}, booktitle = {Ewa Orlowska on Relational Methods in Logic and Computer Science}, publisher = {Springer}, series = {Outstanding Contributions to Logic}, volume = {17}, year = {2018}, pages = {441-479}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/SD-EORM.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/SD-EORM.pdf} }

@article{KS-lmcs19, journal = {Logical Methods in Computer Science}, author = {P. Karandikar and Schnoebelen, {\relax Ph}ilippe}, title = {The height of piecewise-testable languages and the complexity of the logic of subwords}, volume = {15}, number = {2}, pages = {6:1-6:27}, year = {2019}, month = apr, pdf = {https://lmcs.episciences.org/5409/pdf}, url = {https://lmcs.episciences.org/5409}, abstract = {The height of a piecewise-testable language \(L\) is the maximum length of the words needed to define \(L\) by excluding and requiring given subwords. The height of \(L\) is an important descriptive complexity measure that has not yet been investigated in a systematic way. This paper develops a series of new techniques for bounding the height of finite languages and of languages obtained by taking closures by subwords, superwords and related operations. As an application of these results, we show that \(FO^2(A^*,\sqsubseteq)\), the two-variable fragment of the first-order logic of sequences with the subword ordering, can only express piecewise-testable properties and has elementary complexity.} }

@inproceedings{D-time18, address = {Warsaw, Poland}, month = oct, year = 2018, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Natasha Alechina and Kjetil Norvag and Wojciech Penczek}, acronym = {{TIME}'18}, booktitle = {{P}roceedings of the 25th {I}nternational {S}ymposium on {T}emporal {R}epresentation and {R}easoning ({TIME}'18)}, author = {Demri, St{\'e}phane}, title = {On temporal and separation logics}, pages = {1:1-1:4}, url = {http://drops.dagstuhl.de/opus/volltexte/2018/9766/pdf/LIPIcs-TIME-2018-1.pdf} }

@mastersthesis{m2-Hilaire, author = {Hilaire, Mathieu}, title = {{Complexity of the reachability problem for parametric timed automata}}, school = {{M}aster {P}arisien de {R}echerche en {I}nformatique, Paris, France}, type = {Rapport de {M}aster}, year = {2018}, month = sep }

@inproceedings{M-fsttcs18, address = {Ahmedabad, India}, month = dec, year = 2018, volume = {122}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Sumit Ganguly and Paritosh Pandya}, acronym = {{FSTTCS}'18}, booktitle = {{P}roceedings of the 38th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'18)}, author = {Alessio Mansutti}, title = {Extending propositional separation logic for robustness properties}, pages = {42:1-42:23}, url = {http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=9941}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2018/9941/pdf/LIPIcs-FSTTCS-2018-42.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2018.42}, abstract = {We study an extension of propositional separation logic that can specify robustness properties, such as acyclicity and garbage freedom, for automatic verification of stateful programs with singly-linked lists. We show that its satisfiability problem is PSpace-complete, whereas modest extensions of the logic are shown to be Tower-hard. As separating implication, reachability predicates (under some syntactical restrictions) and a unique quantified variable are allowed, this logic subsumes several PSpace-complete separation logics considered in previous works.} }

@inproceedings{FLS-fsttcs18, address = {Ahmedabad, India}, month = dec, year = 2018, volume = {122}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Sumit Ganguly and Paritosh Pandya}, acronym = {{FSTTCS}'18}, booktitle = {{P}roceedings of the 38th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'18)}, author = {Alain Finkel and J{\'e}r{\^o}me Leroux and Gr{\'e}goire Sutre}, title = {Reachability for Two-Counter Machines with One Test and One Reset}, pages = {31:1-31:14}, url = {http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=9930}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2018/9930/pdf/LIPIcs-FSTTCS-2018-31.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2018.31}, abstract = {We prove that the reachability relation of two-counter machines with one zero-test and one reset is Presburger-definable and effectively computable. Our proof is based on the introduction of two classes of Presburger-definable relations effectively stable by transitive closure. This approach generalizes and simplifies the existing different proofs and it solves an open problem introduced by Finkel and Sutre in 2000.} }

@inproceedings{BLS-fsttcs18, address = {Ahmedabad, India}, month = dec, year = 2018, volume = {122}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Sumit Ganguly and Paritosh Pandya}, acronym = {{FSTTCS}'18}, booktitle = {{P}roceedings of the 38th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'18)}, author = {Baelde, David and Lick, Anthony and Schmitz, Sylvain}, title = {A Hypersequent Calculus with Clusters for Tense Logic over Ordinals}, pages = {15:1-15:19}, url = {http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=9914}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2018/9914/pdf/LIPIcs-FSTTCS-2018-15.pdf}, doi = {10.4230/LIPIcs.FSTTCS.2018.15}, abstract = {Prior's tense logic forms the core of linear temporal logic, with both past-and future-looking modalities. We present a sound and complete proof system for tense logic over ordinals. Technically, this is a hypersequent system, enriched with an ordering, clusters, and annotations. The system is designed with proof search algorithms in mind, and yields an optimal coNP complexity for the validity problem. It entails a small model property for tense logic over ordinals: every satisfiable formula has a model of order type at most \(\omega^2\). It also allows to answer the validity problem for ordinals below or exactly equal to a given one.} }

@inproceedings{BLS-pods19, address = {Amsterdam, Netherlands}, month = jun # {-} # jul, publisher = {ACM Press}, editor = {Christoph Koch}, acronym = {{PODS}'19}, booktitle = {{P}roceedings of the 38th {A}nnual {ACM} {SIGACT}-{SIGMOD}-{SIGART} {S}ymposium on {P}rinciples of {D}atabase {S}ystems ({PODS}'19)}, author = {Baelde, David and Lick, Anthony and Schmitz, Sylvain}, title = {Decidable {XP}ath Fragments in the Real World}, pages = {285-302}, year = 2019, doi = {10.1145/3294052.3319685}, url = {https://hal.inria.fr/hal-01852475}, abstract = {XPath is arguably the most popular query language for selecting elements in XML documents. Besides query evaluation, query satisfiability and containment are the main computational problems for XPath; they are useful, for instance, to detect dead code or validate query optimisations. These problems are undecidable in general, but several fragments have been identified over time for which satisfiability (or query containment) is decidable: CoreXPath 1.0 and 2.0 without so-called data joins, fragments with data joins but limited navigation, etc. However, these fragments are often given in a simplified syntax, and sometimes wrt. a simplified XPath semantics. Moreover, they have been studied mostly with theoretical motivations, with little consideration for the practically relevant features of XPath. To investigate the practical impact of these theoretical fragments, we design a benchmark compiling thousands of real-world XPath queries extracted from open-source projects. These queries are then matched against syntactic fragments from the literature. We investigate how to extend these fragments with seldom-considered features such as free variables, data tests, data joins, and the last() and id() functions, for which we provide both undecidability and decidability results. We analyse the coverage of the original and extended fragments, and further provide a glimpse at which other practically-motivated features might be worth investigating in the future.} }

@phdthesis{halfon-phd2018, author = {Halfon, Simon}, title = {On Effective Representations of Well Quasi-Orderings}, school = {{\'E}cole Normale Sup{\'e}rieure Paris-Saclay, France}, type = {Th{\`e}se de doctorat}, year = 2018, month = jun, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/halfon-phd18.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/halfon-phd18.pdf} }

@article{CFMF-fac18, publisher = {Springer}, journal = {Formal Aspects of Computing}, author = {Rapha{\"e}l Chane-Yack-Fa and Marc Frappier and Amel Mammar and Alain Finkel}, title = {{Parameterized Verification of Monotone Information Systems}}, volume = {30}, number = {3-4}, year = {2018}, pages = {463-489}, doi = {10.1007/s00165-018-0460-8}, url = {https://link.springer.com/article/10.1007/s00165-018-0460-8}, abstract = {In this paper, we study the information system verification problem as a parameterized verification one. Informations systems are modeled as multi-parameterized systems in a formal language based on the Algebraic State-Transition Diagrams (ASTD) notation. Then, we use the Well Structured Transition Systems (WSTS) theory to solve the coverability problem for an unbounded ASTD state space. Moreover, we define a new framework to prove the effective pred-basis condition of WSTSs, i.e. the computability of a base of predecessors for every states.} }

@inproceedings{BLS-aiml18, address = {Bern, Switzerland}, month = aug, year = 2018, publisher = {College Publications}, editor = {Guram Bezhanishvili and Giovanna D'Agostino and George Metcalfe and Thomas Studer}, acronym = {{AiML}'18}, booktitle = {{P}roceedings of the 10th {C}onference on {A}dvances in {M}odal {L}ogics ({AiML}'18)}, author = {Baelde, David and Lick, Anthony and Schmitz, Sylvain}, title = {A Hypersequent Calculus with Clusters for Linear Frames}, pages = {36-55}, url = {https://hal.inria.fr/hal-01756126}, abstract = {The logic Kt4.3 is the basic modal logic of linear frames. Along with its extensions, it is found at the core of linear-time temporal logics and logics on words. In this paper, we consider the problem of designing proof systems for these logics, in such a way that proof search yields decision procedures for validity with an optimal complexity---coNP in this case. In earlier work, Indrzejczak has proposed an ordered hypersequent calculus that is sound and complete for Kt4.3 but does not yield any decision procedure. We refine his approach, using a hypersequent structure that corresponds to weak rather than strict total orders, and using annotations that reflect the model-theoretic insights given by small models for Kt4.3. We obtain a sound and complete calculus with an associated coNP proof search algorithm. These results extend naturally to the cases of unbounded and dense frames, and to the complexity of the two-variable fragment of first-order logic over total orders.} }

@inproceedings{DF-aiml18, address = {Bern, Switzerland}, month = aug, year = 2018, publisher = {College Publications}, editor = {Guram Bezhanishvili and Giovanna D'Agostino and George Metcalfe and Thomas Studer}, acronym = {{AiML}'18}, booktitle = {{P}roceedings of the 10th {C}onference on {A}dvances in {M}odal {L}ogics ({AiML}'18)}, author = {Demri, St{\'e}phane and Fervari, Raul}, title = {On the complexity of modal separation logics}, pages = {179-198}, url = {http://www.lsv.fr/Publis/PAPERS/PDF/DF-aiml18.pdf}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DF-aiml18.pdf} }

@article{Z-icomp18, publisher = {Elsevier Science Publishers}, journal = {Information and Computation}, author = {Zetzsche, Georg}, title = {The Emptiness Problem for Valence Automata over Graph Monoids}, year = {2018}, note = {To appear} }

@article{LZ-tocs18, publisher = {Springer}, journal = {Theory of Computing Systems}, author = {Lohrey, Markus and Zetzsche, Georg}, title = {Knapsack in Graph Groups}, volume = {62}, number = {1}, year = {2018}, month = jan, pages = {192-246}, doi = {10.1007/s00224-017-9808-3} }

@article{BHSS-fi18, publisher = {{IOS} Press}, journal = {Fundamenta Informaticae}, author = {B{\'e}atrice B{\'e}rard and Stefan Haar and Sylvain Schmitz and Stefan Schwoon}, title = {{The Complexity of Diagnosability and Opacity Verification for Petri Nets}}, volume = 161, number = 4, year = 2018, pages = {317-349}, doi = {10.3233/FI-2018-1706}, url = {https://hal.inria.fr/hal-01852119}, abstract = {Diagnosability and opacity are two well-studied problems in discrete-event systems. We revisit these two problems with respect to expressiveness and complexity issues. \par We first relate different notions of diagnosability and opacity. We consider in particular fairness issues and extend the definition of Germanos et al. [ACM TECS, 2015] of weakly fair diagnosability for safe Petri nets to general Petri nets and to opacity questions. \par Second, we provide a global picture of complexity results for the verification of diagnosability and opacity. We show that diagnosability is NL-complete for finite state systems, PSPACE-complete for safe convergent Petri nets (even with fairness), and EXPSPACE-complete for general Petri nets without fairness, while non diagnosability is inter-reducible with reachability when fault events are not weakly fair. Opacity is ESPACE-complete for safe Petri nets (even with fairness) and undecidable for general Petri nets already without fairness.} }

@article{ABDL-tcs18, publisher = {Elsevier Science Publishers}, journal = {Theoretical Computer Science}, author = {Alechina, Natasha and Bulling, Nils and Demri, St{\'e}phane and Logan, Brian}, title = {On the Complexity of Resource-Bounded Logics}, volume = {750}, year = {2018}, pages = {69--100}, doi = {10.1016/j.tcs.2018.01.019}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/ABDL-tcs18.pdf} }

@inproceedings{DLM-fossacs18, address = {Thessaloniki, Greece}, month = apr, year = 2018, volume = {10803}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Baier, Christel and {Dal Lago}, Ugo}, acronym = {{FoSSaCS}'18}, booktitle = {{P}roceedings of the 21st {I}nternational {C}onference on {F}oundations of {S}oftware {S}cience and {C}omputation {S}tructures ({FoSSaCS}'18)}, author = {St{\'e}phane Demri and {\'E}tienne Lozes and Alessio Mansutti}, title = {The Effects of Adding Reachability Predicates in Propositional Separation Logic}, pages = {476-493}, pdf = {http://www.lsv.fr/Publis/PAPERS/PDF/DLM-fossacs18.pdf} }

@inproceedings{DLM-csl20, address = {Barcelona, Spain}, month = jan, year = 2020, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Fern{\'a}ndel, Maribel and Muscholl, Anca}, acronym = {{CSL}'20}, booktitle = {{P}roceedings of the 28th {A}nnual {EACSL} {C}onference on {C}omputer {S}cience {L}ogic ({CSL}'20)}, author = {St{\'e}phane Demri and {\'E}tienne Lozes and Alessio Mansutti}, title = {Internal Calculi for Separation Logics}, note = {To appear} }

@inproceedings{GF-fsttcs19, address = {Bombay, India}, month = dec, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Arkadev Chattopadhyay and Paul Gastin}, acronym = {{FSTTCS}'19}, booktitle = {{P}roceedings of the 39th {C}onference on {F}oundations of {S}oftware {T}echnology and {T}heoretical {C}omputer {S}cience ({FSTTCS}'19)}, author = {Ekanshdeep Gupta and Alain Finkel}, title = {The well structured problem for Presburger counter machines}, note = {To appear}, year = 2019 }

@article{DF-jlc19, publisher = {Oxford University Press}, journal = {Journal of Logic and Computation}, author = {Demri, St{\'e}phane and Fervari, Raul}, title = {The power of modal separation logics}, year = 2019, note = {To appear} }

@inproceedings{SZ-rp19, address = {Brussels, Belgium}, month = sep, volume = {11674}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Rapha{\"e}l Jungers and Emmanuel Fillot and Igor Potapov}, acronym = {{RP}'19}, booktitle = {{P}roceedings of the 13th {W}orkshop on {R}eachability {P}roblems in {C}omputational {M}odels ({RP}'19)}, author = {Sylvain Schmitz and Georg Zetzsche}, title = {Coverability Is Undecidable in One-Dimensional Pushdown Vector Addition Systems with Resets}, year = 2019, pages = {193-201}, pdf = {https://arxiv.org/pdf/1906.07069.pdf}, url = {https://arxiv.org/abs/1906.07069}, doi = {10.1007/978-3-030-30806-3_15}, abstract = {We consider the model of pushdown vector addition systems with resets. These consist of vector addition systems that have access to a pushdown stack and have instructions to reset counters. For this model, we study the coverability problem. In the absence of resets, this problem is known to be decidable for one-dimensional pushdown vector addition systems, but decidability is open for general pushdown vector addition systems. Moreover, coverability is known to be decidable for reset vector addition systems without a pushdown stack. We show in this note that the problem is undecidable for one-dimensional pushdown vector addition systems with resets.} }

@inproceedings{FP-concur19, address = {Amsterdam, The Netherlands}, month = aug, volume = {140}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Wan Fokkink and Rob {van Glabbeek}}, acronym = {{CONCUR}'19}, booktitle = {{P}roceedings of the 30th {I}nternational {C}onference on {C}oncurrency {T}heory ({CONCUR}'19)}, author = {Alain Finkel and M. Praveen}, title = {Verification of Flat FIFO Systems}, pages = {12:1-12:17}, year = 2019, doi = {10.4230/LIPIcs.CONCUR.2019.12}, pdf = {http://drops.dagstuhl.de/opus/volltexte/2019/10914/pdf/LIPIcs-CONCUR-2019-12.pdf}, url = {http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=10914}, abstract = {The decidability and complexity of reachability problems and model-checking for flat counter systems have been explored in detail. However, only few results are known for flat FIFO systems, only in some particular cases (a single loop or a single bounded expression). We prove, by establishing reductions between properties, and by reducing SAT to a subset of these properties that many verification problems like reachability, non-termination, unboundedness are NP-complete for flat FIFO systems, generalizing similar existing results for flat counter systems. We construct a trace-flattable counter system that is bisimilar to a given flat FIFO system, which allows to model-check the original flat FIFO system. Our results lay the theoretical foundations and open the way to build a verification tool for (general) FIFO systems based on analysis of flat subsystems.} }

@inproceedings{BD-aamas19, address = {Montreal, Canada}, month = jun, publisher = {ACM Press}, acronym = {{AAMAS}'19}, booktitle = {{P}roceedings of the 18th {I}nternational {J}oint {C}onference on {A}utonomous {A}gents and {M}ulti-{A}gent {S}ystems ({AAMAS}'19)}, author = {Belardinelli, Francesco and Demri, St{\'e}phane}, title = {Resource-bounded ATL: the Quest for Tractable Fragments}, pages = {206--214}, year = 2019, pdf = {http://www.ifaamas.org/Proceedings/aamas2019/pdfs/p206.pdf}, url = {http://www.ifaamas.org/Proceedings/aamas2019/forms/contents.htm#3F} }

@inproceedings{Schmitz-icalp19, address = {Patras, Greece}, month = jul, volume = {132}, series = {Leibniz International Proceedings in Informatics}, publisher = {Leibniz-Zentrum f{\"u}r Informatik}, editor = {Chatzigiannakis, Ioannis and Merelli, Emanuela}, acronym = {{ICALP}'19}, booktitle = {{P}roceedings of the 46th {I}nternational {C}olloquium on {A}utomata, {L}anguages and {P}rogramming ({ICALP}'19)}, author = {Schmitz, Sylvain}, title = {The Parametric Complexity of Lossy Counter Machines}, year = 2019, pages = {129:1-129:15}, doi = {10.4230/LIPIcs.ICALP.2019.129}, pdf = {https://hal.archives-ouvertes.fr/hal-02020728v2/document}, url = {http://drops.dagstuhl.de/opus/volltexte/2019/10705/}, abstract = {The reachability problem in lossy counter machines is the best-known ACKERMANN-complete problem and has been used to establish most of the ACKERMANN-hardness statements in the literature. This hides however a complexity gap when the number of counters is fixed. We close this gap and prove F_d-completeness for machines with d counters, which provides the first known uncontrived problems complete for the fast-growing complexity classes at levels 3 < d < omega. We develop for this an approach through antichain factorisations of bad sequences and analysing the length of controlled antichains.} }

@inproceedings{DFM-jelia19, address = {Rende, Italy}, month = jun, year = 2019, volume = 11468, series = {Lecture Notes in Artificial Intelligence}, publisher = {Springer}, editor = {Calimeri, Francesco and Leone, Nicola and Manna, Marco}, acronym = {{JELIA}'19}, booktitle = {{P}roceedings of the 16th {E}uropean {C}onference on {L}ogics in {A}rtificial {I}ntelligence ({JELIA}'19)}, author = {Demri, St{\'e}phane and Fervari, Raul and Mansutti, Alessio}, title = {Axiomatising logics with separating conjunctions and modalities}, pages = {692-708}, url = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DFM-jelia19.pdf}, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/DFM-jelia19.pdf}, doi = {10.1007/978-3-030-19570-0_45} }

@article{HS-ipl19, publisher = {Elsevier Science Publishers}, journal = {Information Processing Letters}, author = {Halfon, Simon and Schnoebelen, {\relax Ph}ilippe}, title = {On shuffle products, acyclic automata and piecewise-testable languages}, volume = {145}, pages = {68-73}, year = 2019, doi = {10.1016/j.ipl.2019.01.012}, abstract = {We show that the shuffle $L\unicode{x29E2} F$ of a piecewise-testable language $L$ and a finite language $F$ is piecewise-testable. The proof relies on a classic but little-used automata-theoretic characterization of piecewise-testable languages. We also discuss some mild generalizations of the main result, and provide bounds on the piecewise complexity of $L\unicode{x29E2} F$.} }

@inproceedings{FHK-atpn19, address = {Aachen, Germany}, month = jun, year = 2019, volume = {11522}, series = {Lecture Notes in Computer Science}, publisher = {Springer}, editor = {Susanna Donatelli and Stefan Haar}, acronym = {{PETRI~NETS}'19}, booktitle = {{P}roceedings of the 40th {I}nternational {C}onference on {A}pplications and {T}heory of {P}etri {N}ets ({PETRI~NETS}'19)}, author = {Finkel, Alain and Haddad, Serge and Khmelnitsky, Igor}, title = {Coverability and Termination in Recursive Petri Nets}, pages = { 429-448}, url = {https://hal.inria.fr/hal-02081019}, pdf = {https://hal.inria.fr/hal-02081019/document}, doi = {10.1007/978-3-030-21571-2_23}, abstract = {In the early two-thousands, Recursive Petri nets have been introduced in order to model distributed planning of multi-agent systems for which counters and recursivity were necessary. Although Recursive Petri nets strictly extend Petri nets and stack automata, most of the usual property problems are solvable but using non primitive recursive algorithms, even for coverability and termination. For almost all other extended Petri nets models containing a stack the complexity of coverability and termination are unknown or strictly larger than EXPSPACE. In contrast, we establish here that for Recursive Petri nets, the coverability and termination problems are EXPSPACE-complete as for Petri nets. From an expressiveness point of view, we show that coverability languages of Recursive Petri nets strictly include the union of coverability languages of Petri nets and context-free languages. Thus we get for free a more powerful model than Petri net.} }

@inproceedings{BD-lics19, address = {Vancouver, Canada}, month = jun, publisher = {{IEEE} Press}, editor = {Bouyer, Patricia}, acronym = {{LICS}'19}, booktitle = {{P}roceedings of the 34th {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'19)}, author = {Bednarczyk, Bartosz and Demri, St{\'e}phane}, title = {Why propositional quantification makes modal logics on trees robustly hard ?}, pages = {1-13}, year = 2019, pdf = {http://www.lsv.ens-cachan.fr/Publis/PAPERS/PDF/BD-lics2019.pdf}, doi = {10.1109/LICS.2019.8785656} }

@inproceedings{LS-lics19, address = {Vancouver, Canada}, month = jun, publisher = {{IEEE} Press}, editor = {Bouyer, Patricia}, acronym = {{LICS}'19}, booktitle = {{P}roceedings of the 34th {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'19)}, author = {J{\'e}r{\^o}me Leroux and Schmitz, Sylvain}, title = {Reachability in Vector Addition Systems is Primitive-Recursive in Fixed Dimension}, pages = {1-13}, year = 2019, doi = {10.1109/LICS.2019.8785796}, url = {https://arxiv.org/abs/1903.08575}, abstract = {The reachability problem in vector addition systems is a central question, not only for the static verification of these systems, but also for many inter-reducible decision problems occurring in various fields. The currently best known upper bound on this problem is not primitive-recursive, even when considering systems of fixed dimension. We provide significant refinements to the classical decomposition algorithm of Mayr, Kosaraju, and Lambert and to its termination proof, which yield an ACKERMANN upper bound in the general case, and primitive-recursive upper bounds in fixed dimension. While this does not match the currently best known TOWER lower bound for reachability, it is optimal for related problems.} }

@article{LS-icomp19, publisher = {Elsevier Science Publishers}, journal = {Information and Computation}, author = {Ranko Lazi\'c and Sylvain Schmitz}, title = {The Ideal View on {R}ackoff's Coverability Technique}, url = {https://hal.inria.fr/hal-01176755}, year = 2019, note = {To appear}, abstract = {Well-structured transition systems form a large class of infinite-state systems, for which safety verification is decidable thanks to a generic backward coverability algorithm. However, for several classes of systems, the generic upper bounds one can extract from the algorithm are far from optimal. In particular, in the case of vector addition systems (VAS) and several of their extensions, the known tight upper bounds were rather derived thanks to ad-hoc arguments based on Rackoff's small witness property. We show how to derive the same bounds directly on the computations of the VAS instantiation of the generic backward coverability algorithm. This relies on a dual view of the algorithm using ideal decompositions of downwards-closed sets, which exhibits a key structural invariant in the VAS case. This reasoning offers a uniform setting for all well-structured transition systems, including branching ones, and we further apply it to several VAS extensions: we derive optimal upper bounds for coverability in branching and alternating VAS, matching the previously known results from the literature.} }

@inproceedings{JS-lics19, address = {Vancouver, Canada}, month = jun, publisher = {{IEEE} Press}, editor = {Bouyer, Patricia}, acronym = {{LICS}'19}, booktitle = {{P}roceedings of the 34th {A}nnual {ACM\slash IEEE} {S}ymposium on {L}ogic {I}n {C}omputer {S}cience ({LICS}'19)}, author = {Jan{\v c}ar, Petr and Schmitz, Sylvain}, title = {Bisimulation Equivalence of First-Order Grammars is {ACKERMANN}-Complete}, pages = {1-12}, year = 2019, doi = {10.1109/LICS.2019.8785848}, url = {https://arxiv.org/abs/1901.07170}, abstract = {Checking whether two pushdown automata with restricted silent actions are weakly bisimilar was shown decidable by S{\'e}nizergues (1998, 2005). We provide the first known complexity upper bound for this famous problem, in the equivalent setting of first-order grammars. This ACKERMANN upper bound is optimal, and we also show that strong bisimilarity is primitive-recursive when the number of states of the automata is fixed.} }

*This file was generated by
bibtex2html 1.98.*