,
Sylvain Schmitz
,
Henry Sinclair-Banks
Creative Commons Attribution 4.0 International license
We investigate the parameterised complexity of the classic coverability problem for vector addition systems (VAS): V ⊆ ℤ^d, an initial configuration s ∈ ℕ^d, and a target configuration t ∈ ℕ^d, decide whether starting from s, one can iteratively add vectors from V to ultimately arrive at a configuration that is larger than or equal to t on every coordinate, while not observing any negative value on any coordinate along the way. We consider two natural parameters for the problem: the dimension d and the size of V, defined as the total bitsize of its encoding. We present several results charting the complexity of those two parameterisations, among which the highlight is that coverability for VAS parameterised by the dimension and with all the numbers in the input encoded in unary is complete for the class XNL under PL-reductions. We also discuss open problems in the topic, most notably the question about fixed-parameter tractability for the parameterisation by the size of V.
@InProceedings{pilipczuk_et_al:LIPIcs.IPEC.2025.24,
author = {Pilipczuk, Micha{\l} and Schmitz, Sylvain and Sinclair-Banks, Henry},
title = {{A Note on the Parameterised Complexity of Coverability in Vector Addition Systems}},
booktitle = {20th International Symposium on Parameterized and Exact Computation (IPEC 2025)},
pages = {24:1--24:19},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-407-9},
ISSN = {1868-8969},
year = {2025},
volume = {358},
editor = {Agrawal, Akanksha and van Leeuwen, Erik Jan},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.IPEC.2025.24},
URN = {urn:nbn:de:0030-drops-251563},
doi = {10.4230/LIPIcs.IPEC.2025.24},
annote = {Keywords: vector addition system, Petri net, parameterised complexity, coverability}
}