Justifications and a Reconstruction of Parity Game Solving Algorithms

Abstract

Parity games are infinite two-player games played on directed graphs. Parity game solvers are used in the domain of formal verification. This paper defines parametrized parity games and introduces an operation, Justify, that determines a winning strategy for a single node. By carefully ordering Justify steps, we reconstruct three algorithms well known from the literature. Verification and parity game solvingTime logics such as LTL are used to express properties of interacting systems. Synthesis consists of extracting an implementation with the desired properties.