,
Sascha Klüppelholz
,
Timm Spork
Creative Commons Attribution 4.0 International license
Families of deterministic finite automata (FDFA) have been introduced as a concise automaton model that characterizes ω-regular languages by processing their ultimately periodic words. FDFA are known to enjoy many good properties and can be exponentially more succinct than deterministic ω-automata with Rabin, Streett or parity acceptance. This paper addresses two main questions: (1) Are FDFA suitable for probabilistic model checking purposes? and (2) Is it possible to obtain an even more compact representation of ω-regular languages by allowing the components of an FDFA to be unambiguous instead of deterministic? Question (1) is answered in the affirmative by presenting the first polynomial-time algorithm for computing the probability that a discrete-time Markov chain satisfies an ω-regular property represented as an FDFA. Question (2) is motivated by the fact that unambiguous finite automata may require exponentially fewer states than deterministic ones. This paper introduces a model of families of unambiguous finite automata (FUFA) that captures the class of ω-regular languages. FUFA can be exponentially more succinct than both FDFA and unambiguous Büchi automata, and there is a single-exponential translation from linear temporal logic (LTL) to FUFA. This stands in contrast to a double-exponential lower bound for the translation from LTL to FDFA. Moreover, the polynomial-time probabilistic model checking algorithm for discrete-time Markov chains against FDFA-specifications is extended to the case where the property is represented by an FUFA with a deterministic leading automaton.
@InProceedings{baier_et_al:LIPIcs.CONCUR.2026.15,
author = {Baier, Christel and Kl\"{u}ppelholz, Sascha and Spork, Timm},
title = {{Probabilistic Model Checking via Families of Deterministic and Unambiguous Finite Automata}},
booktitle = {37th International Conference on Concurrency Theory (CONCUR 2026)},
pages = {15:1--15:19},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-447-5},
ISSN = {1868-8969},
year = {2026},
volume = {391},
editor = {Sokolova, Ana and Totzke, Patrick},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CONCUR.2026.15},
URN = {urn:nbn:de:0030-drops-273461},
doi = {10.4230/LIPIcs.CONCUR.2026.15},
annote = {Keywords: Families of Finite Automata, FDFA, Unambiguous Automata, Discrete-time Markov Chains, Probabilistic Model Checking, Verification}
}