CSP Bounded Model Checking of Preprocessed CTL Extended with Events Using Answer Set Programming

Abstract

Model checking is a mainstream method for formal verification of communicating sequential processes (CSP). Existing CSP Model Checkers are incapable of verifying multiple properties concurrently in one run of a model checker. In addition, the properties to be verified are described with CSP in most model checkers, which is good for refinement checking, but leads to limited description power and weak generality. In order to tackle the two problems, answer set programming(ASP), which is completely free of sequential dependencies, is used to construct a CSP bounded model checking framework, where the CSP model checking problem is turned into a computation problem of answer sets. CTL is extended with events to describe the properties to be verified. In addition, preprocessing technique of properties is proposed for the sake of reducing the expense spending on replicated verification of the same sub formulas. An ASP based description system is constructed for complete description of various CSP processes and automatic generation of parallel processes. We integrated all the methods into a CSP model checker - ACSPChecker. The feasibility and efficiency of our methods are illustrated by the experiments with a classic concurrency problem - dining philosophers problem.