,
Jérémy Ledent
,
Krzysztof Ziemiański
Creative Commons Attribution 4.0 International license
Higher-dimensional automata (HDA) are a model of concurrency that models simultaneous execution of events using higher dimensional cells. HDA recognize languages of pomsets, a generalization of finite words whose letters are partially ordered. We prove a new algebraic characterization of HDA languages: a language of pomsets is regular if and only if it is the inverse image of a functor from the category of pomsets into a finite category. Furthermore, the language is definable in first-order logic exactly when it is recognized by an aperiodic category, generalizing the McNaughton-Papert theorem to HDA languages. We also investigate a notion of counter-free HDA, and show that if a language is accepted by a counter-free HDA, it must be definable in first-order logic. The converse, however, is still open.
@InProceedings{erlich_et_al:LIPIcs.CONCUR.2026.32,
author = {Erlich, Enzo and Ledent, J\'{e}r\'{e}my and Ziemia\'{n}ski, Krzysztof},
title = {{Algebraic Characterization of FO-Definable Languages of Higher-Dimensional Automata}},
booktitle = {37th International Conference on Concurrency Theory (CONCUR 2026)},
pages = {32:1--32:18},
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.2026.32},
URN = {urn:nbn:de:0030-drops-273620},
doi = {10.4230/LIPIcs.CONCUR.2026.32},
annote = {Keywords: Higher-dimensional automata, Pomset languages, McNaughton-Papert theorem, Counter-free HDA, Aperiodic category}
}