Stuttering Equivalence for Parity Games

TL;DR

This paper explores how stuttering equivalence can be used to simplify parity games, leading to faster solving times without affecting the outcome, as demonstrated through experimental results.

Contribution

It introduces the application of stuttering equivalence to parity games and shows its effectiveness in speeding up the solving process.

Findings

Stuttering equivalent vertices have the same winner in parity games.

Minimising game graphs by stuttering equivalence accelerates solving.

Experimental results show speed-ups in typical verification problems.

Abstract

We study the process theoretic notion of stuttering equivalence in the setting of parity games. We demonstrate that stuttering equivalent vertices have the same winner in the parity game. This means that solving a parity game can be accelerated by minimising the game graph with respect to stuttering equivalence. While, at the outset, it might not be clear that this strategy should pay off, our experiments using typical verification problems illustrate that stuttering equivalence speeds up solving parity games in many cases.