Creative Commons Attribution 4.0 International license
Open parity games are proposed as a compositional extension of parity games with algebraic operations, forming string diagrams of parity games. A potential application of string diagrams of parity games is to describe a large parity game with a given compositional structure and solve it efficiently as a divide-and-conquer algorithm by exploiting its compositional structure. Building on our recent progress in open Markov decision processes, we introduce Pareto fronts of open parity games, offering a framework for multi-objective solutions. We establish the positional determinacy of open parity games with respect to their Pareto fronts through a novel translation method. Our translation converts an open parity game into a parity game tailored to a given single-objective. Furthermore, we present a simple algorithm for solving open parity games, derived from this translation that allows the application of existing efficient algorithms for parity games. Expanding on this foundation, we develop a compositional algorithm for string diagrams of parity games.
@InProceedings{watanabe:LIPIcs.CALCO.2025.14,
author = {Watanabe, Kazuki},
title = {{Pareto Fronts for Compositionally Solving String Diagrams of Parity Games}},
booktitle = {11th Conference on Algebra and Coalgebra in Computer Science (CALCO 2025)},
pages = {14:1--14:20},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-383-6},
ISSN = {1868-8969},
year = {2025},
volume = {342},
editor = {C\^{i}rstea, Corina and Knapp, Alexander},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CALCO.2025.14},
URN = {urn:nbn:de:0030-drops-235734},
doi = {10.4230/LIPIcs.CALCO.2025.14},
annote = {Keywords: parity game, compositionality, string diagram}
}