The reachability problem for vector addition systems with states (VASS) has been shown to be \textsc{Ackermann}-complete. For every k≥3, a completeness result for the k-dimensional VASS reachability problem is not yet available. It is shown in this paper that the 3-dimensional VASS reachability problem is in \textsc{Tower}, improving upon the current best upper bound F7 established by Leroux and Schmidt in 2019.
Cite
@article{arxiv.2306.05710,
title = {Reachability in 3-VASS is in Tower},
author = {Qizhe Yang and Yuxi Fu},
journal= {arXiv preprint arXiv:2306.05710},
year = {2023}
}