English

Cyclic system for an algebraic theory of alternating parity automata

Logic in Computer Science 2025-05-15 v1 Formal Languages and Automata Theory Logic

Abstract

ω\omega-regular languages are a natural extension of the regular languages to the setting of infinite words. Likewise, they are recognised by a host of automata models, one of the most important being Alternating Parity Automata (APAs), a generalisation of B\"uchi automata that symmetrises both the transitions (with universal as well as existential branching) and the acceptance condition (by a parity condition). In this work we develop a cyclic proof system manipulating APAs, represented by an algebraic notation of Right Linear Lattice expressions. This syntax dualises that of previously introduced Right Linear Algebras, which comprised a notation for non-deterministic finite automata (NFAs). This dualisation induces a symmetry in the proof systems we design, with lattice operations behaving dually on each side of the sequent. Our main result is the soundness and completeness of our system for ω\omega-language inclusion, heavily exploiting game theoretic techniques from the theory of ω\omega-regular languages.

Keywords

Cite

@article{arxiv.2505.09000,
  title  = {Cyclic system for an algebraic theory of alternating parity automata},
  author = {Anupam Das and Abhishek De},
  journal= {arXiv preprint arXiv:2505.09000},
  year   = {2025}
}

Comments

26 pages, 3 figures