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arXiv · 2412.02618

Nondeterministic tree-walking automata are not closed under complementation

Olga Martynova·Alexander Okhotin
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Abstract

It is proved that the family of tree languages recognized by nondeterministic tree-walking automata is not closed under complementation, solving a problem raised by Boja\'nczyk and Colcombet ("Tree-walking automata do not recognize all regular languages", SIAM J. Comp. 38 (2008) 658--701). In addition, it is shown that nondeterministic tree-walking automata are stronger than unambiguous tree-walking automata.

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Olga Martynova, Alexander Okhotin. 2024-12-03. Nondeterministic tree-walking automata are not closed under complementation. https://arxiv.org/abs/2412.02618

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