We investigate the connection between properties of formal languages and properties of their generating series, with a focus on the class of holonomic power series. We first prove a strong version of a conjecture by Castiglione and Massazza: weakly-unambiguous Parikh automata are equivalent to unambiguous two-way reversal bounded counter machines, and their multivariate generating series are holonomic. We then show that the converse is not true: we construct a language whose generating series is algebraic (thus holonomic), but which is inherently weakly-ambiguous as a Parikh automata language. Finally, we prove an effective decidability result for the inclusion problem for weakly-unambiguous Parikh automata, and provide an upper-bound on its complexity.
@InProceedings{bostan_et_al:LIPIcs.ICALP.2020.114, author = {Bostan, Alin and Carayol, Arnaud and Koechlin, Florent and Nicaud, Cyril}, title = {{Weakly-Unambiguous Parikh Automata and Their Link to Holonomic Series}}, booktitle = {47th International Colloquium on Automata, Languages, and Programming (ICALP 2020)}, pages = {114:1--114:16}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, ISBN = {978-3-95977-138-2}, ISSN = {1868-8969}, year = {2020}, volume = {168}, editor = {Czumaj, Artur and Dawar, Anuj and Merelli, Emanuela}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICALP.2020.114}, URN = {urn:nbn:de:0030-drops-125212}, doi = {10.4230/LIPIcs.ICALP.2020.114}, annote = {Keywords: generating series, holonomicity, ambiguity, reversal bounded counter machine, Parikh automata} }
Feedback for Dagstuhl Publishing