Reduced Models for Efficient CCS Verification

Abstract

Verification of a concurrent system can be accomplished by model checking the properties on a structure representing the system; this structure is, in general, a transition system which contains a prohibitive number of states. In this paper, we apply a method to reduce the state explosion problem by pointing out the events of the system to be ignored on the basis of the property to be verified. We evaluate the method by means of a real application used as a case study: the system is specified by a CCS program, then the program is reduced by means of syntactic rules; afterwards, the corresponding transition system is built by means of a non-standard operational semantics, which performs further reductions during the construction. Prototype tools perform both kinds of reductions; finally the required properties are checked by means of the model checkers of the CWB-NC.