Modal and Temporal Logics

Modal and temporal logics are logical formalisms with possible world semantics, used for reasoning about a variety of phenomena such as the behaviour of programs, software systems, ethical norms, knowledge, and agential action. Canonical examples involve the basic modal logic K, linear-time temporal logic LTL, branching-time logics like CTL or CTL*, dynamic epistemic logic, and STIT logics. The research includes establishing the precise complexity of standard reasoning problems as well as designing efficient proof systems.

Scientific Staff

Dr. Tim Lyon

Computational Logic

Former Members

Bartosz Bednarczyk

Former Research Associate
Computational Logic

Journal Articles

Tim Lyon, Kees van Berkel
Proof Theory and Decision Procedures for Deontic STIT Logics
Journal of Artificial Intelligence Research, to appear
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Bartosz Bednarczyk, Stéphane Demri, Raul Fervari, Alessio Mansutti
On Composing Finite Forests with Modal Logics
ACM Transactions on Computational Logic, 24(2), April 2023
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Kees van Berkel, Tim Lyon, Matteo Pascucci
A Logical Analysis of Instrumentality Judgments: Means-End Relations in the Context of Experience and Expectations
Journal of Philosophical Logic, 52:1475–1516, 2023
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Bartosz Bednarczyk, Stéphane Demri
Why Does Propositional Quantification Make Modal and Temporal Logics on Trees Robustly Hard?
Logical Methods in Computer Science, Volume 18, Issue 3(5), July 2022
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Bartosz Bednarczyk, Emanuel Kieroński, Piotr Witkowski
Completing the Picture: Complexity of Graded Modal Logics with Converse
Theory and Practice of Logic Programming, 21(4):493--520, April 2021
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Agata Ciabattoni, Tim Lyon, Revantha Ramanayake, Alwen Tiu
Display to Labeled Proofs and Back Again for Tense Logics
ACM Transactions on Computational Logic, 22(3):1-31, August 2021
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Tim Lyon
On the Correspondence between Nested Calculi and Semantic Systems for Intuitionistic Logics
Journal of Logic and Computation, 31(1):213-265, 2021
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Proceedings Articles

Tim Lyon
Unifying Sequent Systems for Gödel-Löb Provability Logic via Syntactic Transformations
In Jörg Endrullis, Sylvain Schmitz, eds., Proceedings of the 33rd EACSL Annual Conference on Computer Science Logic 2025, volume 326 of LIPIcs, to appear. Schloss Dagstuhl - Leibniz-Zentrum für Informatik
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Tim Lyon
On Explicit Solutions to Fixed-Point Equations in Propositional Dynamic Logic
Proceedings of the Eleventh International Conference on Fundamentals of Software Engineering (FSEN), LNCS, to appear. Springer
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Tim Lyon, Ian Shillito, Alwen Tiu
Taking Bi-Intuitionistic Logic First-Order: A Proof-Theoretic Investigation via Polytree Sequents
In Jörg Endrullis, Sylvain Schmitz, eds., Proceedings of the 33rd EACSL Annual Conference on Computer Science Logic 2025, volume 326 of LIPIcs, to appear. Schloss Dagstuhl - Leibniz-Zentrum für Informatik
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Nicholas Leisegang, Thomas Meyer, Sebastian Rudolph
Towards Propositional KLM-Style Defeasible Standpoint Logics
In Aurona Gerber, Jacques Maritz, Anban W. Pillay, eds., Proceedings of the 5th Southern African Conference on AI Research (SACAIR'24), volume 2326 of CCIS, 459–475, 2024. Springer
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Raven Beutner, David Carral, Bernd Finkbeiner, Jana Hofmann, Markus Krötzsch
Deciding Hyperproperties Combined with Functional Specifications
In Christel Baier and Dana Fisman, eds., Proceedings of the 37th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS 2022), 56:1--56:13, 2022. ACM
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Bartosz Bednarczyk, Jakub Michaliszyn
"Most of" leads to undecidability: Failure of adding frequencies to LTL
In Stefan Kiefer, Christine Tasson, eds., Proceedings of the Foundations of Software Science and Computation Structures - 24th International Conference (FOSSACS 2021), volume 12650 of Lecture Notes in Computer Science, 82--101, March 2021. Springer
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Tim Lyon
A Framework for Intuitionistic Grammar Logics
In Pietro Baroni, Christoph Benzmüller, Yὶ N. Wang, eds., Logic and Argumentation, volume 13040, 495-503, October 2021. Springer International Publishing
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Tim Lyon
Nested Sequents for Intuitionistic Modal Logics via Structural Refinement
In Anupam Das, Sara Negri, eds., Automated Reasoning with Analytic Tableaux and Related Methods, 409-427, August 2021. Springer International Publishing
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Kees van Berkel, Tim Lyon
The Varieties of Ought-implies-Can and Deontic STIT Logic
In Fenrong Liu, Alessandra Marra, Paul Portner and Frederik Van De Putte, eds., Deontic Logic and Normative Systems: 15th International Conference, DEON 2020/2021, 57-76, July 2021. College Publications
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Bartosz Bednarczyk, Stéphane Demri, Raul Fervari, Alessio Mansutti
Modal Logics with Composition on Finite Forests: Expressivity and Complexity
In Holger Hermanns, Lijun Zhang, Naoki Kobayashi, Dale Miller, eds., Proceedings of the 35th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS 2020), 167--180, June 2020. ACM
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Bartosz Bednarczyk, Piotr Witkowski
A note on C2 interpreted over finite data-words
In Emilio Muñoz-Velasco, Ana Ozaki, Martin Theobald, eds., Proceedings of the 27th International Symposium on Temporal Representation and Reasoning (TIME 2020), volume 178 of Leibniz International Proceedings in Informatics, 17:1--17:14, September 2020. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik
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Tim Lyon, Alwen Tiu, Rajeev Goré, Ranald Clouston
Syntactic Interpolation for Tense Logics and Bi-Intuitionistic Logic via Nested Sequents
In Maribel Fernández and Anca Muscholl, eds., 28th EACSL Annual Conference on Computer Science Logic (CSL 2020), volume 152, 28:1--28:16, 2020. Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik
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Kees van Berkel, Tim Lyon, Francesco Olivieri
A Decidable Multi-agent Logic for Reasoning About Actions, Instruments, and Norms
Logic and Argumentation, volume 12061, 219-241, 2020. Springer
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Bartosz Bednarczyk, Stéphane Demri
Why propositional quantification makes modal logics on trees robustly hard ?
Proceedings of the 34th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS 2019), 1--13, June 2019. IEEE
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Bartosz Bednarczyk, Emanuel Kieroński, Piotr Witkowski
On the Complexity of Graded Modal Logics with Converse.
In Francesco Calimeri, Nicola Leone, Marco Manna, eds., Proceedings of Logics in Artificial Intelligence - 16th European Conference (JELIA 2019), volume 11468 of LNCS, 642--658, May 2019. Lecture Notes in Computer Science
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Kees van Berkel, Tim Lyon
Cut-Free Calculi and Relational Semantics for Temporal STIT Logics
In Calimeri, Francesco and Leone, Nicola and Manna, Marco, eds., Logics in Artificial Intelligence, volume 11468, 803-819, 2019. Springer
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Kees van Berkel, Tim Lyon
A Neutral Temporal Deontic STIT Logic
In Blackburn, Patrick and Lorini, Emiliano and Guo, Meiyun, eds., Logic, Rationality, and Interaction, volume 11813, 340-354, 2019. Springer
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Tim Lyon, Agata Ciabattoni, Revantha Ramanayake
From Display to Labelled Proofs for Tense Logics
In Artemov, Sergei and Nerode, Anil, eds., From Display to Labelled Proofs for Tense Logics, volume 10703, 120-139, 2018. Springer International Publishing
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Bartosz Bednarczyk, Witold Charatonik, Emanuel Kieroński
Extending Two-Variable Logic on Trees
In Valentin Goranko, Mads Dam, eds., Proceedings of 26th EACSL Annual Conference on Computer Science Logic (CSL 2017), volume 82 of Leibniz International Proceedings in Informatics, 11:1--11:20, August 2017. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik
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Bartosz Bednarczyk, Witold Charatonik
Modulo Counting on Words and Trees.
In Satya V. Lokam, R. Ramanujam, eds., FSTTCS 2017, 37th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, volume 93 of Leibniz International Proceedings in Informatics, 12:1--12:16, December 2017. Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik
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Doctoral Theses

Tim Lyon
Refining Labelled Systems for Modal and Constructive Logics with Applications
Phd thesis, Technische Universität Wien, 2021/07/29
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