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Unboundedness Problems for Formal Languages (Invited Talk)

Author Georg Zetzsche

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Subject Classification

ACM Subject Classification
  • Theory of computation → Models of computation
Keywords
  • Decidability
  • formal languages
  • unifying frameworks
  • downward closure
  • separability

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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 Get BibTex

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) https://doi.org/10.4230/LIPIcs.FSTTCS.2025.2

Author Details

Georg Zetzsche
  • Max Planck Institute for Software Systems (MPI-SWS), Kaiserslautern, Germany

Funding

Funded by the European Union (ERC, FINABIS, 101077902). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council Executive Agency. Neither the European Union nor the granting authority can be held responsible for them.

References

  1. Parosh Aziz Abdulla, Mohamed Faouzi Atig, Vrunda Dave, and Shankara Narayanan Krishna. On the separability problem of string constraints. In Igor Konnov and Laura Kovács, editors, 31st International Conference on Concurrency Theory, CONCUR 2020, September 1-4, 2020, Vienna, Austria (Virtual Conference), volume 171 of LIPIcs, pages 16:1-16:19. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2020. URL: https://doi.org/10.4230/LIPICS.CONCUR.2020.16.
  2. Parosh Aziz Abdulla, Kārlis Čerāns, Bengt Jonsson, and Yih-Kuen Tsay. Algorithmic analysis of programs with well quasi-ordered domains. Inf. Comput., 160(1-2):109-127, 2000. URL: https://doi.org/10.1006/inco.1999.2843.
  3. C. Aiswarya, Pascal Baumann, Prakash Saivasan, Lia Schütze, and Georg Zetzsche. Bounded treewidth, multiple context-free grammars, and downward closures, 2026. To appear. Google Scholar
  4. C. Aiswarya, Paul Gastin, and K. Narayan Kumar. Verifying communicating multi-pushdown systems via split-width. In Franck Cassez and Jean-François Raskin, editors, Automated Technology for Verification and Analysis - 12th International Symposium, ATVA 2014, Sydney, NSW, Australia, November 3-7, 2014, Proceedings, volume 8837 of Lecture Notes in Computer Science, pages 1-17. Springer, 2014. URL: https://doi.org/10.1007/978-3-319-11936-6_1.
  5. Ashwani Anand, Sylvain Schmitz, Lia Schütze, and Georg Zetzsche. Verifying unboundedness via amalgamation. In Pawel Sobocinski, Ugo Dal Lago, and Javier Esparza, editors, Proceedings of the 39th Annual ACM/IEEE Symposium on Logic in Computer Science, LICS 2024, Tallinn, Estonia, July 8-11, 2024, pages 4:1-4:15. ACM, 2024. URL: https://doi.org/10.1145/3661814.3662133.
  6. Ashwani Anand and Georg Zetzsche. Priority downward closures. In Guillermo A. Pérez and Jean-François Raskin, editors, 34th International Conference on Concurrency Theory, CONCUR 2023, September 18-23, 2023, Antwerp, Belgium, volume 279 of LIPIcs, pages 39:1-39:18. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. URL: https://doi.org/10.4230/LIPICS.CONCUR.2023.39.
  7. Mohamed Faouzi Atig, Ahmed Bouajjani, and Shaz Qadeer. Context-bounded analysis for concurrent programs with dynamic creation of threads. Log. Methods Comput. Sci., 7(4), 2011. URL: https://doi.org/10.2168/LMCS-7(4:4)2011.
  8. Pablo Barceló, Diego Figueira, and Rémi Morvan. Separating automatic relations. In Jérôme Leroux, Sylvain Lombardy, and David Peleg, editors, 48th International Symposium on Mathematical Foundations of Computer Science, MFCS 2023, August 28 to September 1, 2023, Bordeaux, France, volume 272 of LIPIcs, pages 17:1-17:15. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. URL: https://doi.org/10.4230/LIPICS.MFCS.2023.17.
  9. David Barozzini, Lorenzo Clemente, Thomas Colcombet, and Pawel Parys. Cost automata, safe schemes, and downward closures. Fundam. Informaticae, 188(3):127-178, 2022. URL: https://doi.org/10.3233/FI-222145.
  10. David Barozzini, Pawel Parys, and Jan Wroblewski. Unboundedness for recursion schemes: A simpler type system. In Mikolaj Bojanczyk, Emanuela Merelli, and David P. Woodruff, editors, 49th International Colloquium on Automata, Languages, and Programming, ICALP 2022, July 4-8, 2022, Paris, France, volume 229 of LIPIcs, pages 112:1-112:19. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2022. URL: https://doi.org/10.4230/LIPIcs.ICALP.2022.112.
  11. Pascal Baumann, Flavio D'Alessandro, Moses Ganardi, Oscar H. Ibarra, Ian McQuillan, Lia Schütze, and Georg Zetzsche. Unboundedness problems for machines with reversal-bounded counters. In Orna Kupferman and Pawel Sobocinski, editors, Foundations of Software Science and Computation Structures - 26th International Conference, FoSSaCS 2023, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2023, Paris, France, April 22-27, 2023, Proceedings, volume 13992 of Lecture Notes in Computer Science, pages 240-264. Springer, 2023. URL: https://doi.org/10.1007/978-3-031-30829-1_12.
  12. Pascal Baumann, Moses Ganardi, Rupak Majumdar, Ramanathan S. Thinniyam, and Georg Zetzsche. Checking refinement of asynchronous programs against context-free specifications. In Kousha Etessami, Uriel Feige, and Gabriele Puppis, editors, 50th International Colloquium on Automata, Languages, and Programming, ICALP 2023, July 10-14, 2023, Paderborn, Germany, volume 261 of LIPIcs, pages 110:1-110:20. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. URL: https://doi.org/10.4230/LIPICS.ICALP.2023.110.
  13. Pascal Baumann, Moses Ganardi, Rupak Majumdar, Ramanathan S. Thinniyam, and Georg Zetzsche. Context-bounded analysis of concurrent programs (invited talk). In Kousha Etessami, Uriel Feige, and Gabriele Puppis, editors, 50th International Colloquium on Automata, Languages, and Programming, ICALP 2023, July 10-14, 2023, Paderborn, Germany, volume 261 of LIPIcs, pages 3:1-3:16. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. URL: https://doi.org/10.4230/LIPICS.ICALP.2023.3.
  14. Pascal Baumann, Eren Keskin, Roland Meyer, and Georg Zetzsche. Separability in Büchi VASS and singly non-linear systems of inequalities. In Karl Bringmann, Martin Grohe, Gabriele Puppis, and Ola Svensson, editors, 51st International Colloquium on Automata, Languages, and Programming, ICALP 2024, July 8-12, 2024, Tallinn, Estonia, volume 297 of LIPIcs, pages 126:1-126:19. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2024. URL: https://doi.org/10.4230/LIPICS.ICALP.2024.126.
  15. Pascal Baumann, Rupak Majumdar, Ramanathan S. Thinniyam, and Georg Zetzsche. The complexity of bounded context switching with dynamic thread creation. In Artur Czumaj, Anuj Dawar, and Emanuela Merelli, editors, 47th International Colloquium on Automata, Languages, and Programming, ICALP 2020, July 8-11, 2020, Saarbrücken, Germany (Virtual Conference), volume 168 of LIPIcs, pages 111:1-111:16. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2020. URL: https://doi.org/10.4230/LIPICS.ICALP.2020.111.
  16. Pascal Baumann, Rupak Majumdar, Ramanathan S. Thinniyam, and Georg Zetzsche. Context-bounded verification of thread pools. Proc. ACM Program. Lang., 6(POPL):1-28, 2022. URL: https://doi.org/10.1145/3498678.
  17. Pascal Baumann, Roland Meyer, and Georg Zetzsche. Regular separability in Büchi VASS. In Petra Berenbrink, Patricia Bouyer, Anuj Dawar, and Mamadou Moustapha Kanté, editors, 40th International Symposium on Theoretical Aspects of Computer Science, STACS 2023, March 7-9, 2023, Hamburg, Germany, volume 254 of LIPIcs, pages 9:1-9:19. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. URL: https://doi.org/10.4230/LIPICS.STACS.2023.9.
  18. Mikolaj Bojanczyk. It is undecidable if two regular tree languages can be separated by a deterministic tree-walking automaton. Fundam. Informaticae, 154(1-4):37-46, 2017. URL: https://doi.org/10.3233/FI-2017-1551.
  19. Luca Breveglieri, Alessandra Cherubini, Claudio Citrini, and Stefano Crespi-Reghizzi. Multi-push-down languages and grammars. Int. J. Found. Comput. Sci., 7(3):253-292, 1996. URL: https://doi.org/10.1142/S0129054196000191.
  20. Lorenzo Clemente, Wojciech Czerwiński, Slawomir Lasota, and Charles Paperman. Regular Separability of Parikh Automata. In Ioannis Chatzigiannakis, Piotr Indyk, Fabian Kuhn, and Anca Muscholl, editors, 44th International Colloquium on Automata, Languages, and Programming (ICALP 2017), volume 80 of Leibniz International Proceedings in Informatics (LIPIcs), pages 117:1-117:13, Dagstuhl, Germany, 2017. Schloss Dagstuhl - Leibniz-Zentrum für Informatik. URL: https://doi.org/10.4230/LIPIcs.ICALP.2017.117.
  21. Lorenzo Clemente, Wojciech Czerwiński, Slawomir Lasota, and Charles Paperman. Separability of reachability sets of vector addition systems. In Heribert Vollmer and Brigitte Vallée, editors, 34th Symposium on Theoretical Aspects of Computer Science, STACS 2017, March 8-11, 2017, Hannover, Germany, volume 66 of LIPIcs, pages 24:1-24:14. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017. URL: https://doi.org/10.4230/LIPICS.STACS.2017.24.
  22. Lorenzo Clemente, Pawel Parys, Sylvain Salvati, and Igor Walukiewicz. The diagonal problem for higher-order recursion schemes is decidable. In Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science, LICS '16, New York, NY, USA, July 5-8, 2016, pages 96-105. ACM, 2016. URL: https://doi.org/10.1145/2933575.2934527.
  23. Lorenzo Clemente and Michal Skrzypczak. Deterministic and game separability for regular languages of infinite trees. In Nikhil Bansal, Emanuela Merelli, and James Worrell, editors, 48th International Colloquium on Automata, Languages, and Programming, ICALP 2021, July 12-16, 2021, Glasgow, Scotland (Virtual Conference), volume 198 of LIPIcs, pages 126:1-126:15. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2021. URL: https://doi.org/10.4230/LIPICS.ICALP.2021.126.
  24. Elias Rojas Collins, Chris Köcher, and Georg Zetzsche. The complexity of separability for semilinear sets and parikh automata. In Pawel Gawrychowski, Filip Mazowiecki, and Michal Skrzypczak, editors, 50th International Symposium on Mathematical Foundations of Computer Science, MFCS 2025, August 25-29, 2025, Warsaw, Poland, volume 345 of LIPIcs, pages 38:1-38:21. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2025. URL: https://doi.org/10.4230/LIPICS.MFCS.2025.38.
  25. Bruno Courcelle. The monadic second-order logic of graphs, II: infinite graphs of bounded width. Math. Syst. Theory, 21(4):187-221, 1989. URL: https://doi.org/10.1007/BF02088013.
  26. Aiswarya Cyriac. Verification of communicating recursive programs via split-width. (Vérification de programmes récursifs et communicants via split-width). PhD thesis, École normale supérieure de Cachan, France, 2014. URL: https://tel.archives-ouvertes.fr/tel-01015561.
  27. Aiswarya Cyriac, Paul Gastin, and K. Narayan Kumar. MSO decidability of multi-pushdown systems via split-width. In Maciej Koutny and Irek Ulidowski, editors, CONCUR 2012 - Concurrency Theory - 23rd International Conference, CONCUR 2012, Newcastle upon Tyne, UK, September 4-7, 2012. Proceedings, volume 7454 of Lecture Notes in Computer Science, pages 547-561. Springer, 2012. URL: https://doi.org/10.1007/978-3-642-32940-1_38.
  28. Wojciech Czerwinski, Piotr Hofman, and Georg Zetzsche. Unboundedness problems for languages of vector addition systems. In Ioannis Chatzigiannakis, Christos Kaklamanis, Dániel Marx, and Donald Sannella, editors, 45th International Colloquium on Automata, Languages, and Programming, ICALP 2018, July 9-13, 2018, Prague, Czech Republic, volume 107 of LIPIcs, pages 119:1-119:15. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018. URL: https://doi.org/10.4230/LIPICS.ICALP.2018.119.
  29. Wojciech Czerwiński and Slawomir Lasota. Regular separability of one counter automata. In 32nd Annual ACM/IEEE Symposium on Logic in Computer Science, LICS 2017, Reykjavik, Iceland, June 20-23, 2017, pages 1-12. IEEE Computer Society, 2017. URL: https://doi.org/10.1109/LICS.2017.8005079.
  30. Wojciech Czerwinski, Slawomir Lasota, Roland Meyer, Sebastian Muskalla, K. Narayan Kumar, and Prakash Saivasan. Regular separability of well-structured transition systems. In Sven Schewe and Lijun Zhang, editors, 29th International Conference on Concurrency Theory, CONCUR 2018, September 4-7, 2018, Beijing, China, volume 118 of LIPIcs, pages 35:1-35:18. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018. URL: https://doi.org/10.4230/LIPICS.CONCUR.2018.35.
  31. Wojciech Czerwinski, Wim Martens, Lorijn van Rooijen, Marc Zeitoun, and Georg Zetzsche. A characterization for decidable separability by piecewise testable languages. Discret. Math. Theor. Comput. Sci., 19(4), 2017. URL: https://doi.org/10.23638/DMTCS-19-4-1.
  32. Wojciech Czerwinski and Georg Zetzsche. An approach to regular separability in vector addition systems. In Holger Hermanns, Lijun Zhang, Naoki Kobayashi, and Dale Miller, editors, LICS '20: 35th Annual ACM/IEEE Symposium on Logic in Computer Science, Saarbrücken, Germany, July 8-11, 2020, pages 341-354. ACM, 2020. URL: https://doi.org/10.1145/3373718.3394776.
  33. Alain Finkel, Shankara Narayanan Krishna, Khushraj Madnani, Rupak Majumdar, and Georg Zetzsche. Counter machines with infrequent reversals. In Patricia Bouyer and Srikanth Srinivasan, editors, 43rd IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, FSTTCS 2023, December 18-20, 2023, IIIT Hyderabad, Telangana, India, volume 284 of LIPIcs, pages 42:1-42:17. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. URL: https://doi.org/10.4230/LIPICS.FSTTCS.2023.42.
  34. Alain Finkel and Ph Schnoebelen. Well-structured transition systems everywhere! Theoretical Computer Science, 256(1-2):63-92, 2001. URL: https://doi.org/10.1016/S0304-3975(00)00102-X.
  35. Jean Goubault-Larrecq and Sylvain Schmitz. Deciding piecewise testable separability for regular tree languages. In Ioannis Chatzigiannakis, Michael Mitzenmacher, Yuval Rabani, and Davide Sangiorgi, editors, 43rd International Colloquium on Automata, Languages, and Programming, ICALP 2016, July 11-15, 2016, Rome, Italy, volume 55 of LIPIcs, pages 97:1-97:15. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2016. URL: https://doi.org/10.4230/LIPICS.ICALP.2016.97.
  36. Matthew Hague, Jonathan Kochems, and C.-H. Luke Ong. Unboundedness and downward closures of higher-order pushdown automata. In POPL 2016: Principles of Programming Languages, pages 151-163. ACM, 2016. URL: https://doi.org/10.1145/2837614.2837627.
  37. Leonard H Haines. On free monoids partially ordered by embedding. Journal of Combinatorial Theory, 6(1):94-98, 1969. URL: https://doi.org/10.1016/S0021-9800(69)80111-0.
  38. Graham Higman. Ordering by divisibility in abstract algebras. Proceedings of The London Mathematical Society, pages 326-336, 1952. URL: https://doi.org/10.1112/PLMS/S3-2.1.326.
  39. Petr Jancar. Decidability of a temporal logic problem for Petri nets. Theor. Comput. Sci., 74(1):71-93, 1990. URL: https://doi.org/10.1016/0304-3975(90)90006-4.
  40. Eren Keskin and Roland Meyer. Separability and non-determinizability of WSTS. In Guillermo A. Pérez and Jean-François Raskin, editors, 34th International Conference on Concurrency Theory, CONCUR 2023, September 18-23, 2023, Antwerp, Belgium, volume 279 of LIPIcs, pages 8:1-8:17. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. URL: https://doi.org/10.4230/LIPICS.CONCUR.2023.8.
  41. Eren Keskin and Roland Meyer. On the separability problem of VASS reachability languages. In Pawel Sobocinski, Ugo Dal Lago, and Javier Esparza, editors, Proceedings of the 39th Annual ACM/IEEE Symposium on Logic in Computer Science, LICS 2024, Tallinn, Estonia, July 8-11, 2024, pages 49:1-49:14. ACM, 2024. URL: https://doi.org/10.1145/3661814.3662116.
  42. Chris Köcher and Georg Zetzsche. Regular separators for VASS coverability languages. In Patricia Bouyer and Srikanth Srinivasan, editors, 43rd IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, FSTTCS 2023, December 18-20, 2023, IIIT Hyderabad, Telangana, India, volume 284 of LIPIcs, pages 15:1-15:19. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023. URL: https://doi.org/10.4230/LIPICS.FSTTCS.2023.15.
  43. Eryk Kopczynski. Invisible pushdown languages. In Martin Grohe, Eric Koskinen, and Natarajan Shankar, editors, Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science, LICS '16, New York, NY, USA, July 5-8, 2016, pages 867-872. ACM, 2016. URL: https://doi.org/10.1145/2933575.2933579.
  44. Salvatore La Torre, Parthasarathy Madhusudan, and Gennaro Parlato. A robust class of context-sensitive languages. In 22nd IEEE Symposium on Logic in Computer Science (LICS 2007), 10-12 July 2007, Wroclaw, Poland, Proceedings, pages 161-170. IEEE Computer Society, 2007. URL: https://doi.org/10.1109/LICS.2007.9.
  45. Salvatore La Torre, Anca Muscholl, and Igor Walukiewicz. Safety of parametrized asynchronous shared-memory systems is almost always decidable. In Luca Aceto and David de Frutos-Escrig, editors, 26th International Conference on Concurrency Theory, CONCUR 2015, Madrid, Spain, September 1.4, 2015, volume 42 of LIPIcs, pages 72-84. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2015. URL: https://doi.org/10.4230/LIPICS.CONCUR.2015.72.
  46. Salvatore La Torre, Margherita Napoli, and Gennaro Parlato. A unifying approach for multistack pushdown automata. In Erzsébet Csuhaj-Varjú, Martin Dietzfelbinger, and Zoltán Ésik, editors, Mathematical Foundations of Computer Science 2014 - 39th International Symposium, MFCS 2014, Budapest, Hungary, August 25-29, 2014. Proceedings, Part I, volume 8634 of Lecture Notes in Computer Science, pages 377-389. Springer, 2014. URL: https://doi.org/10.1007/978-3-662-44522-8_32.
  47. Salvatore La Torre, Margherita Napoli, and Gennaro Parlato. Reachability of scope-bounded multistack pushdown systems. Inf. Comput., 275:104588, 2020. URL: https://doi.org/10.1016/J.IC.2020.104588.
  48. Jérôme Leroux. Vector addition system reachability problem: a short self-contained proof. In Thomas Ball and Mooly Sagiv, editors, Proceedings of the 38th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, POPL 2011, Austin, TX, USA, January 26-28, 2011, pages 307-316. ACM, 2011. URL: https://doi.org/10.1145/1926385.1926421.
  49. Jérôme Leroux, M. Praveen, Philippe Schnoebelen, and Grégoire Sutre. On functions weakly computable by pushdown Petri nets and related systems. Log. Methods Comput. Sci., 15(4), 2019. URL: https://doi.org/10.23638/LMCS-15(4:15)2019.
  50. Jérôme Leroux and Sylvain Schmitz. Demystifying reachability in vector addition systems. In 30th Annual ACM/IEEE Symposium on Logic in Computer Science, LICS 2015, Kyoto, Japan, July 6-10, 2015, pages 56-67. IEEE Computer Society, 2015. URL: https://doi.org/10.1109/LICS.2015.16.
  51. P. Madhusudan and Gennaro Parlato. The tree width of auxiliary storage. SIGPLAN Not., 46(1):283-294, 2011. URL: https://doi.org/10.1145/1925844.1926419.
  52. Rupak Majumdar, Ramanathan S. Thinniyam, and Georg Zetzsche. General decidability results for asynchronous shared-memory programs: Higher-order and beyond. Log. Methods Comput. Sci., 18(4), 2022. URL: https://doi.org/10.46298/LMCS-18(4:2)2022.
  53. Pawel Parys. The complexity of the diagonal problem for recursion schemes. In Satya V. Lokam and R. Ramanujam, editors, 37th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, FSTTCS 2017, December 11-15, 2017, Kanpur, India, volume 93 of LIPIcs, pages 45:1-45:14. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017. URL: https://doi.org/10.4230/LIPIcs.FSTTCS.2017.45.
  54. Thomas Place and Marc Zeitoun. Separation for dot-depth two. Log. Methods Comput. Sci., 17(3), 2021. URL: https://doi.org/10.46298/LMCS-17(3:24)2021.
  55. Thomas Place and Marc Zeitoun. A generic polynomial time approach to separation by first-order logic without quantifier alternation. In Anuj Dawar and Venkatesan Guruswami, editors, 42nd IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, FSTTCS 2022, December 18-20, 2022, IIT Madras, Chennai, India, volume 250 of LIPIcs, pages 43:1-43:22. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2022. URL: https://doi.org/10.4230/LIPICS.FSTTCS.2022.43.
  56. Thomas Place and Marc Zeitoun. Group separation strikes back. In 38th Annual ACM/IEEE Symposium on Logic in Computer Science, LICS 2023, Boston, MA, USA, June 26-29, 2023, pages 1-13. IEEE, 2023. URL: https://doi.org/10.1109/LICS56636.2023.10175683.
  57. Shaz Qadeer and Jakob Rehof. Context-bounded model checking of concurrent software. In Nicolas Halbwachs and Lenore D. Zuck, editors, Tools and Algorithms for the Construction and Analysis of Systems, 11th International Conference, TACAS 2005, Held as Part of the Joint European Conferences on Theory and Practice of Software, ETAPS 2005, Edinburgh, UK, April 4-8, 2005, Proceedings, volume 3440 of Lecture Notes in Computer Science, pages 93-107. Springer, 2005. URL: https://doi.org/10.1007/978-3-540-31980-1_7.
  58. Hiroyuki Seki, Takashi Matsumura, Mamoru Fujii, and Tadao Kasami. On multiple context-free grammars. Theor. Comput. Sci., 88(2):191-229, 1991. URL: https://doi.org/10.1016/0304-3975(91)90374-B.
  59. Ramanathan S. Thinniyam and Georg Zetzsche. Regular separability and intersection emptiness are independent problems. In Arkadev Chattopadhyay and Paul Gastin, editors, 39th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, FSTTCS 2019, December 11-13, 2019, Bombay, India, volume 150 of LIPIcs, pages 51:1-51:15. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2019. URL: https://doi.org/10.4230/LIPICS.FSTTCS.2019.51.
  60. Georg Zetzsche. An approach to computing downward closures. In Magnús M. Halldórsson, Kazuo Iwama, Naoki Kobayashi, and Bettina Speckmann, editors, Automata, Languages, and Programming - 42nd International Colloquium, ICALP 2015, Kyoto, Japan, July 6-10, 2015, Proceedings, Part II, volume 9135 of Lecture Notes in Computer Science, pages 440-451. Springer, 2015. URL: https://doi.org/10.1007/978-3-662-47666-6_35.
  61. Georg Zetzsche. Monoids as Storage Mechanisms. PhD thesis, Kaiserslautern University of Technology, Germany, 2016. URL: https://nbn-resolving.org/urn:nbn:de:hbz:386-kluedo-44003.
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