Alternating hierarchy of sushifts defined by nondeterministic plane-walking automata

Autor:	de Menibus, Benjamin Hellouin, Perrotin, Pacôme
Rok vydání:	2024
Předmět:	Computer Science - Formal Languages and Automata Theory 68Q45 37B51 68Q10 F.4.3 F.1.2
Druh dokumentu:	Working Paper
Popis:	Plane-walking automata were introduced by Salo & T\"orma to recognise languages of two-dimensional infinite words (subshifts), the counterpart of $4$-way finite automata for two-dimensional finite words. We extend the model to allow for nondeterminism and alternation of quantifiers. We prove that the recognised subshifts form a strict subclass of sofic subshifts, and that the classes corresponding to existential and universal nondeterminism are incomparable and both larger that the deterministic class. We define a hierarchy of subshifts recognised by plane-walking automata with alternating quantifiers, which we conjecture to be strict. Comment: 14 pages, submitted to STACS 2025
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2409.08024 Zobrazit plný text záznamu View this record from Arxiv