$ω$-regular Expression Synthesis from Transition-Based Büchi Automata

Charles Pert; Dalal Alrajeh; Alessandra Russo

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arXiv · 2406.08136

$ω$-regular Expression Synthesis from Transition-Based Büchi Automata

Charles Pert·Dalal Alrajeh·Alessandra Russo

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Abstract

A popular method for modelling reactive systems is to use $ω$-regular languages. These languages can be represented as nondeterministic Büchi automata (NBAs) or $ω$-regular expressions. Existing methods synthesise expressions from state-based NBAs. Synthesis from transition-based NBAs is traditionally done by transforming transition-based NBAs into state-based NBAs. This transformation, however, can increase the complexity of the synthesised expressions. This paper proposes a novel method for directly synthesising $ω$-regular expressions from transition-based NBAs. We prove that the method is sound and complete. Our empirical results show that the $ω$-regular expressions synthesised from transition-based NBAs are more compact than those synthesised from state-based NBAs. This is particularly the case for NBAs computed from obligation, reactivity, safety and recurrence-type LTL formulas, reporting in the latter case an average reduction of over 50%. We also show that our method successfully synthesises $ω$-regular expressions from more LTL formulas when using a transition-based instead of a state-based NBA.

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BibTeX RIS

Charles Pert, Dalal Alrajeh, Alessandra Russo. 2024-06-12. $ω$-regular Expression Synthesis from Transition-Based Büchi Automata. https://arxiv.org/abs/2406.08136

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