Bisimilarity on Basic Parallel Processes

Abstract

The main aim of this paper is to give a simple transparent proof of the result showing that the problem of bisimulation equivalence on the class of Basic Parallel Processes (BPP), denoted by BPP-Bisim, can be decided by a polynomial-space algorithm. This result (by the author) has been previously only presented in a conference version, in a rather technical form that is not easily readable and verifiable. Since the result has clarified the complexity of the problem BPP-Bisim, namely its PSPACE-completeness (using the lower bound by Srba), and the problem deals with a fundamental behavioural equivalence and with one of the simplest models that naturally extend finite-state systems into infinite-state ones, it seems appropriate to have a transparent version of the proof.