,
Łukasz Orlikowski
Creative Commons Attribution 4.0 International license
The aim of this paper is to deliver broad understanding of a class of languages of boundedly-ambiguous VASSs, that is k-ambiguous VASSs for some natural k. These are languages of Vector Addition Systems with States with the acceptance condition defined by the set of accepting states such that each accepted word has at most k accepting runs. We develop tools for proving that a given language is not accepted by any k-ambiguous VASS. Using them we show a few negative results: lack of some closure properties of languages of k-ambiguous VASSs and undecidability of the k-ambiguity problem, namely the question whether a given VASS language is a language of some k-ambiguous VASS. In fact we show an even more general undecidability result stating that for any class containing all regular languages and only k-ambiguous VASS languages for some k ∈ ℕ it is undecidable whether a language of a given 1-dimensional VASS belongs to this class. Finally, we show that the regularity problem is decidable for k-ambiguous VASSs.
@InProceedings{czerwinski_et_al:LIPIcs.CONCUR.2025.13,
author = {Czerwi\'{n}ski, Wojciech and Orlikowski, {\L}ukasz},
title = {{Languages of Boundedly-Ambiguous Vector Addition Systems with States}},
booktitle = {36th International Conference on Concurrency Theory (CONCUR 2025)},
pages = {13:1--13:23},
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.2025.13},
URN = {urn:nbn:de:0030-drops-239635},
doi = {10.4230/LIPIcs.CONCUR.2025.13},
annote = {Keywords: vector addition systems, Petri nets, unambiguity, bounded-ambiguity, languages}
}