69 Search Results for "Konnov, Igor"


Volume

LIPIcs, Volume 171

31st International Conference on Concurrency Theory (CONCUR 2020)

CONCUR 2020, September 1-4, 2020, Vienna, Austria (Virtual Conference)

Editors: Igor Konnov and Laura Kovács

Document
One-Clock Synthesis Problems

Authors: Sławomir Lasota, Mathieu Lehaut, Julie Parreaux, and Radosław Piórkowski

Published in: LIPIcs, Volume 364, 43rd International Symposium on Theoretical Aspects of Computer Science (STACS 2026)


Abstract
We study a generalisation of Büchi-Landweber games to the timed setting. The winning condition is specified by a non-deterministic timed automaton, and one of the players can elapse time. We perform a systematic study of synthesis problems in all variants of timed games, depending on which player’s winning condition is specified, and which player’s strategy (or controller, a finite-memory strategy) is sought. As our main result we prove ubiquitous undecidability in all the variants, both for strategy and controller synthesis, already for winning conditions specified by one-clock automata. This strengthens and generalises previously known undecidability results. We also fully characterise those cases where finite memory is sufficient to win, namely existence of a strategy implies existence of a controller. All our results are stated in the timed setting, while analogous results hold in the data setting where one-clock automata are replaced by one-register ones.

Cite as

Sławomir Lasota, Mathieu Lehaut, Julie Parreaux, and Radosław Piórkowski. One-Clock Synthesis Problems. In 43rd International Symposium on Theoretical Aspects of Computer Science (STACS 2026). Leibniz International Proceedings in Informatics (LIPIcs), Volume 364, pp. 64:1-64:21, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)


Copy BibTex To Clipboard

@InProceedings{lasota_et_al:LIPIcs.STACS.2026.64,
  author =	{Lasota, S{\l}awomir and Lehaut, Mathieu and Parreaux, Julie and Pi\'{o}rkowski, Rados{\l}aw},
  title =	{{One-Clock Synthesis Problems}},
  booktitle =	{43rd International Symposium on Theoretical Aspects of Computer Science (STACS 2026)},
  pages =	{64:1--64:21},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-412-3},
  ISSN =	{1868-8969},
  year =	{2026},
  volume =	{364},
  editor =	{Mahajan, Meena and Manea, Florin and McIver, Annabelle and Thắng, Nguy\~{ê}n Kim},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.STACS.2026.64},
  URN =		{urn:nbn:de:0030-drops-255533},
  doi =		{10.4230/LIPIcs.STACS.2026.64},
  annote =	{Keywords: timed automata, register automata, B\"{u}chi-Landweber games, Church synthesis problem, reactive synthesis problem}
}
Document
Parametric Disjunctive Timed Networks

Authors: Étienne André, Swen Jacobs, and Engel Lefaucheux

Published in: LIPIcs, Volume 363, 34th EACSL Annual Conference on Computer Science Logic (CSL 2026)


Abstract
We consider distributed systems with an arbitrary number of processes, modelled by timed automata that communicate through location guards: a process can take a guarded transition if at least one other process is in a given location. In this work, we introduce parametric disjunctive timed networks, where each timed automaton may contain timing parameters, i.e., unknown constants. We investigate two problems: deciding the emptiness of the set of parameter valuations for which 1) a given location is reachable for at least one process (local property), and 2) a global state is reachable where all processes are in a given location (global property). Our main positive result is that the first problem is decidable for networks of processes with a single clock and without invariants; this result holds for arbitrarily many timing parameters - a setting with few known decidability results. However, it becomes undecidable when invariants are allowed, or when considering global properties, even for systems with a single parameter. This highlights the significant expressive power of invariants in these networks. Additionally, we exhibit further decidable subclasses by restraining the syntax of guards and invariants.

Cite as

Étienne André, Swen Jacobs, and Engel Lefaucheux. Parametric Disjunctive Timed Networks. In 34th EACSL Annual Conference on Computer Science Logic (CSL 2026). Leibniz International Proceedings in Informatics (LIPIcs), Volume 363, pp. 31:1-31:24, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)


Copy BibTex To Clipboard

@InProceedings{andre_et_al:LIPIcs.CSL.2026.31,
  author =	{Andr\'{e}, \'{E}tienne and Jacobs, Swen and Lefaucheux, Engel},
  title =	{{Parametric Disjunctive Timed Networks}},
  booktitle =	{34th EACSL Annual Conference on Computer Science Logic (CSL 2026)},
  pages =	{31:1--31:24},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-411-6},
  ISSN =	{1868-8969},
  year =	{2026},
  volume =	{363},
  editor =	{Guerrini, Stefano and K\"{o}nig, Barbara},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CSL.2026.31},
  URN =		{urn:nbn:de:0030-drops-254562},
  doi =		{10.4230/LIPIcs.CSL.2026.31},
  annote =	{Keywords: parametrised verification, parametric timed automata, verification of infinite-state systems}
}
Document
Invited Talk
Unboundedness Problems for Formal Languages (Invited Talk)

Authors: Georg Zetzsche

Published in: LIPIcs, Volume 360, 45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025)


Abstract
Informally, unboundedness problems are decision problems that ask about the existence of infinitely many words (satisfying certain properties) in a formal language. For example: Is a given language infinite? Or: Does a given language have super-polynomial growth? These came into focus in recent years because of their connections to downward closure computation and separability problems. Although unboundedness problems may seem difficult at first, it turns out that there are techniques that are at the same time conceptually very simple, but also apply to a surprisingly wide variety of language classes. The talk will survey recent results (and techniques) concerning unboundedness problems.

Cite as

Georg Zetzsche. Unboundedness Problems for Formal Languages (Invited Talk). In 45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 360, pp. 2:1-2:10, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


Copy BibTex To Clipboard

@InProceedings{zetzsche:LIPIcs.FSTTCS.2025.2,
  author =	{Zetzsche, Georg},
  title =	{{Unboundedness Problems for Formal Languages}},
  booktitle =	{45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025)},
  pages =	{2:1--2:10},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-406-2},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{360},
  editor =	{Aiswarya, C. and Mehta, Ruta and Roy, Subhajit},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSTTCS.2025.2},
  URN =		{urn:nbn:de:0030-drops-250810},
  doi =		{10.4230/LIPIcs.FSTTCS.2025.2},
  annote =	{Keywords: Decidability, formal languages, unifying frameworks, downward closure, separability}
}
Document
Parameterized Verification of Timed Networks with Clock Invariants

Authors: Étienne André, Swen Jacobs, Shyam Lal Karra, and Ocan Sankur

Published in: LIPIcs, Volume 360, 45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025)


Abstract
We consider parameterized verification problems for networks of timed automata (TAs) based on different communication primitives. To this end, we first consider disjunctive timed networks (DTNs), i.e., networks of TAs that communicate via location guards that enable a transition only if there is another process in a certain location. We solve for the first time the case with unrestricted clock invariants, and establish that the parameterized model checking problem (PMCP) over finite local traces can be reduced to the corresponding model checking problem on a single TA. Moreover, we prove that the PMCP for networks that communicate via lossy broadcast can be reduced to the PMCP for DTNs. Finally, we show that for networks with k-wise synchronization, and therefore also for timed Petri nets, location reachability can be reduced to location reachability in DTNs. As a consequence we can answer positively the open problem from Abdulla et al. (2018) whether the universal safety problem for timed Petri nets with multiple clocks is decidable.

Cite as

Étienne André, Swen Jacobs, Shyam Lal Karra, and Ocan Sankur. Parameterized Verification of Timed Networks with Clock Invariants. In 45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 360, pp. 8:1-8:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


Copy BibTex To Clipboard

@InProceedings{andre_et_al:LIPIcs.FSTTCS.2025.8,
  author =	{Andr\'{e}, \'{E}tienne and Jacobs, Swen and Karra, Shyam Lal and Sankur, Ocan},
  title =	{{Parameterized Verification of Timed Networks with Clock Invariants}},
  booktitle =	{45th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2025)},
  pages =	{8:1--8:19},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-406-2},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{360},
  editor =	{Aiswarya, C. and Mehta, Ruta and Roy, Subhajit},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSTTCS.2025.8},
  URN =		{urn:nbn:de:0030-drops-250878},
  doi =		{10.4230/LIPIcs.FSTTCS.2025.8},
  annote =	{Keywords: Networks of Timed Automata, Parameterized Verification, Timed Petri Nets}
}
Document
Just Verification of Mutual Exclusion Algorithms

Authors: Rob van Glabbeek, Bas Luttik, and Myrthe S. C. Spronck

Published in: LIPIcs, Volume 348, 36th International Conference on Concurrency Theory (CONCUR 2025)


Abstract
We verify the correctness of a variety of mutual exclusion algorithms through model checking. We look at algorithms where communication is via shared read/write registers, where those registers can be atomic or non-atomic. For the verification of liveness properties, it is necessary to assume a completeness criterion to eliminate spurious counterexamples. We use justness as completeness criterion. Justness depends on a concurrency relation; we consider several such relations, modelling different assumptions on the working of the shared registers. We present executions demonstrating the violation of correctness properties by several algorithms, and in some cases suggest improvements.

Cite as

Rob van Glabbeek, Bas Luttik, and Myrthe S. C. Spronck. Just Verification of Mutual Exclusion Algorithms. In 36th International Conference on Concurrency Theory (CONCUR 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 348, pp. 17:1-17:25, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


Copy BibTex To Clipboard

@InProceedings{vanglabbeek_et_al:LIPIcs.CONCUR.2025.17,
  author =	{van Glabbeek, Rob and Luttik, Bas and Spronck, Myrthe S. C.},
  title =	{{Just Verification of Mutual Exclusion Algorithms}},
  booktitle =	{36th International Conference on Concurrency Theory (CONCUR 2025)},
  pages =	{17:1--17:25},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-389-8},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{348},
  editor =	{Bouyer, Patricia and van de Pol, Jaco},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CONCUR.2025.17},
  URN =		{urn:nbn:de:0030-drops-239670},
  doi =		{10.4230/LIPIcs.CONCUR.2025.17},
  annote =	{Keywords: Mutual exclusion, safe registers, regular registers, overlapping reads and writes, atomicity, safety, liveness, starvation freedom, justness, model checking, mCRL2}
}
Document
Characterizations of Fragments of Temporal Logic over Mazurkiewicz Traces

Authors: Bharat Adsul, Paul Gastin, and Shantanu Kulkarni

Published in: LIPIcs, Volume 348, 36th International Conference on Concurrency Theory (CONCUR 2025)


Abstract
We study fragments of temporal logics over Mazurkiewicz traces which are well known and established partial-order models of concurrent behaviours. We focus on concurrent versions of "strict past" and "strict future" modalities. Over words, the corresponding fragments have been shown to coincide with natural algebraic conditions on the recognizing monoids. We provide non-trivial generalizations of these classical results to traces. We exploit the local nature of the temporal modalities and obtain modular translations of specifications into asynchronous automata. More specifically, we provide novel characterizations of these fragments via local cascade products of a very simple two-state asynchronous automaton operating on a single process.

Cite as

Bharat Adsul, Paul Gastin, and Shantanu Kulkarni. Characterizations of Fragments of Temporal Logic over Mazurkiewicz Traces. In 36th International Conference on Concurrency Theory (CONCUR 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 348, pp. 5:1-5:20, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


Copy BibTex To Clipboard

@InProceedings{adsul_et_al:LIPIcs.CONCUR.2025.5,
  author =	{Adsul, Bharat and Gastin, Paul and Kulkarni, Shantanu},
  title =	{{Characterizations of Fragments of Temporal Logic over Mazurkiewicz Traces}},
  booktitle =	{36th International Conference on Concurrency Theory (CONCUR 2025)},
  pages =	{5:1--5:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-389-8},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{348},
  editor =	{Bouyer, Patricia and van de Pol, Jaco},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CONCUR.2025.5},
  URN =		{urn:nbn:de:0030-drops-239551},
  doi =		{10.4230/LIPIcs.CONCUR.2025.5},
  annote =	{Keywords: Mazurkiewicz traces, temporal logics, asynchronous automata, cascade product, Green’s relations, algebraic automata theory}
}
Document
Undecidability of the Emptiness Problem for Weak Models of Distributed Computing

Authors: Flavio T. Principato, Javier Esparza, and Philipp Czerner

Published in: LIPIcs, Volume 330, 4th Symposium on Algorithmic Foundations of Dynamic Networks (SAND 2025)


Abstract
Esparza and Reiter have recently conducted a systematic comparative study of weak asynchronous models of distributed computing, in which a network of identical finite-state machines acts cooperatively to decide properties of the network’s graph. They introduced a distributed automata framework encompassing many different models, and proved that w.r.t. their expressive power (the graph properties they can decide) distributed automata collapse into seven equivalence classes. In this contribution, we turn our attention to the formal verification problem: Given a distributed automaton, does it decide a given graph property? We consider a fundamental instance of this question - the emptiness problem: Given a distributed automaton, does it accept any graph at all? Our main result is negative: the emptiness problem is undecidable for six of the seven equivalence classes, and trivially decidable for the remaining class.

Cite as

Flavio T. Principato, Javier Esparza, and Philipp Czerner. Undecidability of the Emptiness Problem for Weak Models of Distributed Computing. In 4th Symposium on Algorithmic Foundations of Dynamic Networks (SAND 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 330, pp. 5:1-5:14, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


Copy BibTex To Clipboard

@InProceedings{principato_et_al:LIPIcs.SAND.2025.5,
  author =	{Principato, Flavio T. and Esparza, Javier and Czerner, Philipp},
  title =	{{Undecidability of the Emptiness Problem for Weak Models of Distributed Computing}},
  booktitle =	{4th Symposium on Algorithmic Foundations of Dynamic Networks (SAND 2025)},
  pages =	{5:1--5:14},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-368-3},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{330},
  editor =	{Meeks, Kitty and Scheideler, Christian},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SAND.2025.5},
  URN =		{urn:nbn:de:0030-drops-230582},
  doi =		{10.4230/LIPIcs.SAND.2025.5},
  annote =	{Keywords: Undecidability, Emptiness Problem, distributed Automata}
}
Document
Identity-Preserving Lax Extensions and Where to Find Them

Authors: Sergey Goncharov, Dirk Hofmann, Pedro Nora, Lutz Schröder, and Paul Wild

Published in: LIPIcs, Volume 327, 42nd International Symposium on Theoretical Aspects of Computer Science (STACS 2025)


Abstract
Generic notions of bisimulation for various types of systems (nondeterministic, probabilistic, weighted etc.) rely on identity-preserving (normal) lax extensions of the functor encapsulating the system type, in the paradigm of universal coalgebra. It is known that preservation of weak pullbacks is a sufficient condition for a functor to admit a normal lax extension (the Barr extension, which in fact is then even strict); in the converse direction, nothing is currently known about necessary (weak) pullback preservation conditions for the existence of normal lax extensions. In the present work, we narrow this gap by showing on the one hand that functors admitting a normal lax extension preserve 1/4-iso pullbacks, i.e. pullbacks in which at least one of the projections is an isomorphism. On the other hand, we give sufficient conditions, showing that a functor admits a normal lax extension if it weakly preserves either 1/4-iso pullbacks and 4/4-epi pullbacks (i.e. pullbacks in which all morphisms are epic) or inverse images. We apply these criteria to concrete examples, in particular to functors modelling neighbourhood systems and weighted systems.

Cite as

Sergey Goncharov, Dirk Hofmann, Pedro Nora, Lutz Schröder, and Paul Wild. Identity-Preserving Lax Extensions and Where to Find Them. In 42nd International Symposium on Theoretical Aspects of Computer Science (STACS 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 327, pp. 40:1-40:20, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


Copy BibTex To Clipboard

@InProceedings{goncharov_et_al:LIPIcs.STACS.2025.40,
  author =	{Goncharov, Sergey and Hofmann, Dirk and Nora, Pedro and Schr\"{o}der, Lutz and Wild, Paul},
  title =	{{Identity-Preserving Lax Extensions and Where to Find Them}},
  booktitle =	{42nd International Symposium on Theoretical Aspects of Computer Science (STACS 2025)},
  pages =	{40:1--40:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-365-2},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{327},
  editor =	{Beyersdorff, Olaf and Pilipczuk, Micha{\l} and Pimentel, Elaine and Thắng, Nguy\~{ê}n Kim},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.STACS.2025.40},
  URN =		{urn:nbn:de:0030-drops-228665},
  doi =		{10.4230/LIPIcs.STACS.2025.40},
  annote =	{Keywords: (Bi-)simulations, lax extensions, modal logics, coalgebra}
}
Document
Quantitative Graded Semantics and Spectra of Behavioural Metrics

Authors: Jonas Forster, Lutz Schröder, Paul Wild, Harsh Beohar, Sebastian Gurke, Barbara König, and Karla Messing

Published in: LIPIcs, Volume 326, 33rd EACSL Annual Conference on Computer Science Logic (CSL 2025)


Abstract
Behavioural metrics provide a quantitative refinement of classical two-valued behavioural equivalences on systems with quantitative data, such as metric or probabilistic transition systems. In analogy to the linear-time/ branching-time spectrum of two-valued behavioural equivalences on transition systems, behavioural metrics vary in granularity, and are often characterized by fragments of suitable modal logics. In the latter respect, the quantitative case is, however, more involved than the two-valued one; in fact, we show that probabilistic metric trace distance cannot be characterized by any compositionally defined modal logic with unary modalities. We go on to provide a unifying treatment of spectra of behavioural metrics in the emerging framework of graded monads, working in coalgebraic generality, that is, parametrically in the system type. In the ensuing development of quantitative graded semantics, we introduce algebraic presentations of graded monads on the category of metric spaces. Moreover, we provide a general criterion for a given real-valued modal logic to characterize a given behavioural distance. As a case study, we apply this criterion to obtain a new characteristic modal logic for trace distance in fuzzy metric transition systems.

Cite as

Jonas Forster, Lutz Schröder, Paul Wild, Harsh Beohar, Sebastian Gurke, Barbara König, and Karla Messing. Quantitative Graded Semantics and Spectra of Behavioural Metrics. In 33rd EACSL Annual Conference on Computer Science Logic (CSL 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 326, pp. 33:1-33:21, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)


Copy BibTex To Clipboard

@InProceedings{forster_et_al:LIPIcs.CSL.2025.33,
  author =	{Forster, Jonas and Schr\"{o}der, Lutz and Wild, Paul and Beohar, Harsh and Gurke, Sebastian and K\"{o}nig, Barbara and Messing, Karla},
  title =	{{Quantitative Graded Semantics and Spectra of Behavioural Metrics}},
  booktitle =	{33rd EACSL Annual Conference on Computer Science Logic (CSL 2025)},
  pages =	{33:1--33:21},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-362-1},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{326},
  editor =	{Endrullis, J\"{o}rg and Schmitz, Sylvain},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CSL.2025.33},
  URN =		{urn:nbn:de:0030-drops-227907},
  doi =		{10.4230/LIPIcs.CSL.2025.33},
  annote =	{Keywords: transition systems, modal logics, coalgebras, behavioural metrics}
}
Document
Swarms of Mobile Robots: Towards Versatility with Safety

Authors: Pierre Courtieu, Lionel Rieg, Sébastien Tixeuil, and Xavier Urbain

Published in: LITES, Volume 8, Issue 2 (2022): Special Issue on Distributed Hybrid Systems. Leibniz Transactions on Embedded Systems, Volume 8, Issue 2


Abstract
We present Pactole, a formal framework to design and prove the correctness of protocols (or the impossibility of their existence) that target mobile robotic swarms. Unlike previous approaches, our methodology unifies in a single formalism the execution model, the problem specification, the protocol, and its proof of correctness. The Pactole framework makes use of the Coq proof assistant, and is specially targeted at protocol designers and problem specifiers, so that a common unambiguous language is used from the very early stages of protocol development. We stress the underlying framework design principles to enable high expressivity and modularity, and provide concrete examples about how the Pactole framework can be used to tackle actual problems, some previously addressed by the Distributed Computing community, but also new problems, while being certified correct.

Cite as

Pierre Courtieu, Lionel Rieg, Sébastien Tixeuil, and Xavier Urbain. Swarms of Mobile Robots: Towards Versatility with Safety. In LITES, Volume 8, Issue 2 (2022): Special Issue on Distributed Hybrid Systems. Leibniz Transactions on Embedded Systems, Volume 8, Issue 2, pp. 02:1-02:36, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)


Copy BibTex To Clipboard

@Article{courtieu_et_al:LITES.8.2.2,
  author =	{Courtieu, Pierre and Rieg, Lionel and Tixeuil, S\'{e}bastien and Urbain, Xavier},
  title =	{{Swarms of Mobile Robots: Towards Versatility with Safety}},
  journal =	{Leibniz Transactions on Embedded Systems},
  pages =	{02:1--02:36},
  ISSN =	{2199-2002},
  year =	{2022},
  volume =	{8},
  number =	{2},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LITES.8.2.2},
  URN =		{urn:nbn:de:0030-drops-192942},
  doi =		{10.4230/LITES.8.2.2},
  annote =	{Keywords: distributed algorithm, mobile autonomous robots, formal proof}
}
Document
Holistic Verification of Blockchain Consensus

Authors: Nathalie Bertrand, Vincent Gramoli, Igor Konnov, Marijana Lazić, Pierre Tholoniat, and Josef Widder

Published in: LIPIcs, Volume 246, 36th International Symposium on Distributed Computing (DISC 2022)


Abstract
Blockchain has recently attracted the attention of the industry due, in part, to its ability to automate asset transfers. It requires distributed participants to reach a consensus on a block despite the presence of malicious (a.k.a. Byzantine) participants. Malicious participants exploit regularly weaknesses of these blockchain consensus algorithms, with sometimes devastating consequences. In fact, these weaknesses are quite common and are well illustrated by the flaws in various blockchain consensus algorithms [Pierre Tholoniat and Vincent Gramoli, 2019]. Paradoxically, until now, no blockchain consensus has been holistically verified. In this paper, we remedy this paradox by model checking for the first time a blockchain consensus used in industry. We propose a holistic approach to verify the consensus algorithm of the Red Belly Blockchain [Tyler Crain et al., 2021], for any number n of processes and any number f < n/3 of Byzantine processes. We decompose directly the algorithm pseudocode in two parts - an inner broadcast algorithm and an outer decision algorithm - each modelled as a threshold automaton [Igor Konnov et al., 2017], and we formalize their expected properties in linear-time temporal logic. We then automatically check the inner broadcasting algorithm, under a carefully identified fairness assumption. For the verification of the outer algorithm, we simplify the model of the inner algorithm by relying on its proven properties. Doing so, we formally verify, for any parameter, not only the safety properties of the Red Belly Blockchain consensus but also its liveness in less than 70 seconds.

Cite as

Nathalie Bertrand, Vincent Gramoli, Igor Konnov, Marijana Lazić, Pierre Tholoniat, and Josef Widder. Holistic Verification of Blockchain Consensus. In 36th International Symposium on Distributed Computing (DISC 2022). Leibniz International Proceedings in Informatics (LIPIcs), Volume 246, pp. 10:1-10:24, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)


Copy BibTex To Clipboard

@InProceedings{bertrand_et_al:LIPIcs.DISC.2022.10,
  author =	{Bertrand, Nathalie and Gramoli, Vincent and Konnov, Igor and Lazi\'{c}, Marijana and Tholoniat, Pierre and Widder, Josef},
  title =	{{Holistic Verification of Blockchain Consensus}},
  booktitle =	{36th International Symposium on Distributed Computing (DISC 2022)},
  pages =	{10:1--10:24},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-255-6},
  ISSN =	{1868-8969},
  year =	{2022},
  volume =	{246},
  editor =	{Scheideler, Christian},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.DISC.2022.10},
  URN =		{urn:nbn:de:0030-drops-172019},
  doi =		{10.4230/LIPIcs.DISC.2022.10},
  annote =	{Keywords: Model checking, automata, logic, byzantine failure}
}
Document
Short Paper
Formal Specification and Model Checking of the Tendermint Blockchain Synchronization Protocol (Short Paper)

Authors: Sean Braithwaite, Ethan Buchman, Igor Konnov, Zarko Milosevic, Ilina Stoilkovska, Josef Widder, and Anca Zamfir

Published in: OASIcs, Volume 84, 2nd Workshop on Formal Methods for Blockchains (FMBC 2020)


Abstract
Blockchain synchronization is one of the core protocols of Tendermint blockchains. In this short paper, we discuss our recent efforts in formal specification of the protocol and its implementation, as well as some initial model checking results. We demonstrate that the protocol quality and understanding can be improved by writing specifications and model checking them.

Cite as

Sean Braithwaite, Ethan Buchman, Igor Konnov, Zarko Milosevic, Ilina Stoilkovska, Josef Widder, and Anca Zamfir. Formal Specification and Model Checking of the Tendermint Blockchain Synchronization Protocol (Short Paper). In 2nd Workshop on Formal Methods for Blockchains (FMBC 2020). Open Access Series in Informatics (OASIcs), Volume 84, pp. 10:1-10:8, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)


Copy BibTex To Clipboard

@InProceedings{braithwaite_et_al:OASIcs.FMBC.2020.10,
  author =	{Braithwaite, Sean and Buchman, Ethan and Konnov, Igor and Milosevic, Zarko and Stoilkovska, Ilina and Widder, Josef and Zamfir, Anca},
  title =	{{Formal Specification and Model Checking of the Tendermint Blockchain Synchronization Protocol}},
  booktitle =	{2nd Workshop on Formal Methods for Blockchains (FMBC 2020)},
  pages =	{10:1--10:8},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-95977-169-6},
  ISSN =	{2190-6807},
  year =	{2020},
  volume =	{84},
  editor =	{Bernardo, Bruno and Marmsoler, Diego},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.FMBC.2020.10},
  URN =		{urn:nbn:de:0030-drops-134238},
  doi =		{10.4230/OASIcs.FMBC.2020.10},
  annote =	{Keywords: Blockchain, Fault Tolerance, Byzantine Faults, Model Checking}
}
Document
Complete Volume
LIPIcs, Volume 171, CONCUR 2020, Complete Volume

Authors: Igor Konnov and Laura Kovács

Published in: LIPIcs, Volume 171, 31st International Conference on Concurrency Theory (CONCUR 2020)


Abstract
LIPIcs, Volume 171, CONCUR 2020, Complete Volume

Cite as

31st International Conference on Concurrency Theory (CONCUR 2020). Leibniz International Proceedings in Informatics (LIPIcs), Volume 171, pp. 1-984, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)


Copy BibTex To Clipboard

@Proceedings{konnov_et_al:LIPIcs.CONCUR.2020,
  title =	{{LIPIcs, Volume 171, CONCUR 2020, Complete Volume}},
  booktitle =	{31st International Conference on Concurrency Theory (CONCUR 2020)},
  pages =	{1--984},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-160-3},
  ISSN =	{1868-8969},
  year =	{2020},
  volume =	{171},
  editor =	{Konnov, Igor and Kov\'{a}cs, Laura},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CONCUR.2020},
  URN =		{urn:nbn:de:0030-drops-128115},
  doi =		{10.4230/LIPIcs.CONCUR.2020},
  annote =	{Keywords: LIPIcs, Volume 171, CONCUR 2020, Complete Volume}
}
Document
Front Matter
Front Matter, Table of Contents, Preface, Conference Organization

Authors: Igor Konnov and Laura Kovács

Published in: LIPIcs, Volume 171, 31st International Conference on Concurrency Theory (CONCUR 2020)


Abstract
Front Matter, Table of Contents, Preface, Conference Organization

Cite as

31st International Conference on Concurrency Theory (CONCUR 2020). Leibniz International Proceedings in Informatics (LIPIcs), Volume 171, pp. 0:i-0:xvi, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)


Copy BibTex To Clipboard

@InProceedings{konnov_et_al:LIPIcs.CONCUR.2020.0,
  author =	{Konnov, Igor and Kov\'{a}cs, Laura},
  title =	{{Front Matter, Table of Contents, Preface, Conference Organization}},
  booktitle =	{31st International Conference on Concurrency Theory (CONCUR 2020)},
  pages =	{0:i--0:xvi},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-160-3},
  ISSN =	{1868-8969},
  year =	{2020},
  volume =	{171},
  editor =	{Konnov, Igor and Kov\'{a}cs, Laura},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CONCUR.2020.0},
  URN =		{urn:nbn:de:0030-drops-128125},
  doi =		{10.4230/LIPIcs.CONCUR.2020.0},
  annote =	{Keywords: Front Matter, Table of Contents, Preface, Conference Organization}
}
  • Refine by Type
  • 68 Document/PDF
  • 9 Document/HTML
  • 1 Volume

  • Refine by Publication Year
  • 2 2026
  • 7 2025
  • 2 2022
  • 54 2020
  • 1 2019
  • Show More...

  • Refine by Author
  • 8 Konnov, Igor
  • 5 Widder, Josef
  • 3 Esparza, Javier
  • 3 Lasota, Sławomir
  • 3 Schröder, Lutz
  • Show More...

  • Refine by Series/Journal
  • 66 LIPIcs
  • 1 OASIcs
  • 1 LITES

  • Refine by Classification
  • 12 Theory of computation → Concurrency
  • 12 Theory of computation → Logic and verification
  • 8 Theory of computation → Formal languages and automata theory
  • 7 Theory of computation → Automata over infinite objects
  • 6 Theory of computation → Distributed computing models
  • Show More...

  • Refine by Keyword
  • 3 Bisimulation
  • 3 Model Checking
  • 3 vector addition systems
  • 2 Asynchrony
  • 2 Axiomatisation
  • Show More...

Any Issues?
X

Feedback on the Current Page

CAPTCHA

Thanks for your feedback!

Feedback submitted to Dagstuhl Publishing

Could not send message

Please try again later or send an E-mail