The Network Satisfaction Problem for Relation Algebras with at most 4 Atoms
Rings and Algebras
2025-07-15 v1 Computational Complexity
Logic
Abstract
Andr\'eka and Maddux classified the relation algebras with at most 3 atoms, and in particular they showed that all of them are representable. Hirsch and Cristiani showed that the network satisfaction problem (NSP) for each of these algebras is in P or NP-hard. There are relation algebras with 4 atoms that are not representable, and there are many results in the literature about representations and non-representability of relation algebras with at most 4 atoms. We extend the result of Hirsch and Cristiani to relation algebras with at most 4 atoms: the NSP is always either in P or NP-hard. To this end, we construct universal, fully universal, or even normal representations for these algebras, whenever possible.
Cite
@article{arxiv.2507.09324,
title = {The Network Satisfaction Problem for Relation Algebras with at most 4 Atoms},
author = {Manuel Bodirsky and Moritz Jahn and Matěj Konečný and Simon Knäuer and Paul Winkler},
journal= {arXiv preprint arXiv:2507.09324},
year = {2025}
}