,
Nathanaël Fijalkow
,
Corto Mascle
Creative Commons Attribution 4.0 International license
Property testing is concerned with the design of algorithms making a sublinear number of queries to distinguish whether the input satisfies a given property or is far from having this property. A seminal paper of Alon, Krivelevich, Newman, and Szegedy in 2001 introduced property testing of formal languages: the goal is to determine whether an input word belongs to a given language, or is far from any word in that language. They constructed the first property testing algorithm for the class of all regular languages. This opened a line of work with improved complexity results and applications to streaming algorithms. In this work, we show a trichotomy result: the class of regular languages can be divided into three classes, each associated with an optimal query complexity. Our analysis yields effective characterizations for all three classes using so-called minimal blocking sequences, reasoning directly and combinatorially on automata.
@InProceedings{bathie_et_al:LIPIcs.ICALP.2025.141,
author = {Bathie, Gabriel and Fijalkow, Nathana\"{e}l and Mascle, Corto},
title = {{The Trichotomy of Regular Property Testing}},
booktitle = {52nd International Colloquium on Automata, Languages, and Programming (ICALP 2025)},
pages = {141:1--141:21},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-372-0},
ISSN = {1868-8969},
year = {2025},
volume = {334},
editor = {Censor-Hillel, Keren and Grandoni, Fabrizio and Ouaknine, Jo\"{e}l and Puppis, Gabriele},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICALP.2025.141},
URN = {urn:nbn:de:0030-drops-235186},
doi = {10.4230/LIPIcs.ICALP.2025.141},
annote = {Keywords: property testing, regular languages}
}