Logics and Games for True Concurrency

TL;DR

This paper develops a unified logical and game-theoretic framework for analyzing concurrent systems with partial order semantics, introducing new mu-calculi and logic games that generalize existing methods and are decidable in finite cases.

Contribution

It introduces a set of mu-calculi and logic games that uniformly capture concurrency behaviors and extend existing bisimulation and model-checking techniques.

Findings

Defined new mu-calculi matching known bisimulation equivalences

Developed infinite higher-order logic games for bisimulation and model-checking

Proved soundness, completeness, and decidability of the proposed games

Abstract

We study the underlying mathematical properties of various partial order models of concurrency based on transition systems, Petri nets, and event structures, and show that the concurrent behaviour of these systems can be captured in a uniform way by two simple and general dualities of local behaviour. Such dualities are used to define new mu-calculi and logic games for the analysis of concurrent systems with partial order semantics. Some results of this work are: the definition of a number of mu-calculi which, in some classes of systems, induce the same identifications as some of the best known bisimulation equivalences for concurrency; and the definition of (infinite) higher-order logic games for bisimulation and model-checking, where the players of the games are given (local) monadic second-order power on the sets of elements they are allowed to play. More specifically, we show that our games are sound and complete, and therefore, determined; moreover, they are decidable in the finite case and underpin novel decision procedures for bisimulation and model-checking. Since these mu-calculi and logic games generalise well-known fixpoint logics and game-theoretic decision procedures for concurrent systems with interleaving semantics, the results herein give some of the groundwork for the design of a logic-based, game-theoretic framework for studying, in a uniform way, several concurrent systems regardless of whether they have an interleaving or a partial order semantics.