English

Emptiness of Stack Automata is NEXPTIME-complete: A Correction

Formal Languages and Automata Theory 2018-05-31 v1

Abstract

A saturation algorithm for collapsible pushdown systems was published in ICALP 2012. This work introduced a class of stack automata used to recognised regular sets of collapsible pushdown configurations. It was shown that these automata form an effective boolean algebra, have a linear time membership problem, and are equivalent to an alternative automata representation appearing in LICS 2010. It was also claimed that the emptiness problem for stack automata is PSPACE-complete. Unfortunately, this claim is not true. We show that the problem is in fact NEXPTIME-complete when the stacks being accepted are collapsible pushdown stacks, rather than the annotated stacks used in ICALP 2012.

Keywords

Cite

@article{arxiv.1805.11873,
  title  = {Emptiness of Stack Automata is NEXPTIME-complete: A Correction},
  author = {Christopher Broadbent and Arnaud Carayol and Matthew Hague and Olivier Serre},
  journal= {arXiv preprint arXiv:1805.11873},
  year   = {2018}
}
R2 v1 2026-06-23T02:13:03.045Z