,
Stéphane Le Roux
Creative Commons Attribution 4.0 International license
Positional determinacy of vertex-colored parity games was proved in the 1990s, which directly implies positional determinacy of edge-colored parity games. In 2006, it was shown that if a prefix-independent color-based objective ensures that every edge-colored two-player turn-based game is positionally determined, this objective is equivalent to a parity objective. We prove a similar result for vertex-colored games, namely that the following are equivalent for any prefix-independent objective W over a finite set of colors: - W is positionally determined on all vertex-colored one-player games. - W is positionally determined on all vertex-colored two-player games. - W is equivalent to a parity objective on ordrerd pairs of colors. We prove that finiteness of the color set is required for our equivalence to hold. Beyond this 1-to-2-player lift, the technique that we develop to handle the pairs of colors establishes a promising 2-way correspondence between edge-colored games and vertex-colored games.
@InProceedings{berthon_et_al:LIPIcs.CONCUR.2026.17,
author = {Berthon, Rapha\"{e}l and Le Roux, St\'{e}phane},
title = {{Positional Determinacy with Colored Vertices: A 1-To-2-Player Lift}},
booktitle = {37th International Conference on Concurrency Theory (CONCUR 2026)},
pages = {17:1--17:18},
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.2026.17},
URN = {urn:nbn:de:0030-drops-273480},
doi = {10.4230/LIPIcs.CONCUR.2026.17},
annote = {Keywords: two-player games, one-player games, parity objectives}
}