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arXiv · 1805.11873

Emptiness of Stack Automata is NEXPTIME-complete: A Correction

Christopher Broadbent·Arnaud Carayol·Matthew Hague·Olivier Serre
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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.

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Christopher Broadbent, Arnaud Carayol, Matthew Hague, Olivier Serre. 2018-05-30. Emptiness of Stack Automata is NEXPTIME-complete: A Correction. https://arxiv.org/abs/1805.11873

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