Towards a homotopy theory of higher dimensional transition systems

TL;DR

This paper develops a homotopy-theoretic framework for higher dimensional transition systems, establishing model structures that relate weak equivalences to process algebra equivalences and bisimulation.

Contribution

It introduces a new model structure for unions of cubes in higher dimensional transition systems, linking weak equivalence to process algebra isomorphism and bisimulation.

Findings

Existence of a left proper combinatorial model structure

Weak equivalence corresponds to isomorphism of process algebra systems

Bousfield localization relates bisimilarity to weak equivalence

Abstract

We proved in a previous work that Cattani-Sassone's higher dimensional transition systems can be interpreted as a small-orthogonality class of a topological locally finitely presentable category of weak higher dimensional transition systems. In this paper, we turn our attention to the full subcategory of weak higher dimensional transition systems which are unions of cubes. It is proved that there exists a left proper combinatorial model structure such that two objects are weakly equivalent if and only if they have the same cubes after simplification of the labelling. This model structure is obtained by Bousfield localizing a model structure which is left determined with respect to a class of maps which is not the class of monomorphisms. We prove that the higher dimensional transition systems corresponding to two process algebras are weakly equivalent if and only if they are isomorphic. We also construct a second Bousfield localization in which two bisimilar cubical transition systems are weakly equivalent. The appendix contains a technical lemma about smallness of weak factorization systems in coreflective subcategories which can be of independent interest. This paper is a first step towards a homotopical interpretation of bisimulation for higher dimensional transition systems.