Enhancing Model Checking in Verification by AI Techniques

Model checking is a fruitful application of computational logic with high relevance to the verification of concurrent systems. While model checking is capable of automatically testing that a concurrent system satisfies its formal specification, it can not precisely locate an error and suggest a repair, i.e., a suitable correction, to the system. In this paper, we tackle this problem by using principles from AI. In particular, we introduce the abstract concept of a system repair problem, and exemplify this concept on repair of concurrent programs and protocols. For the development of our framework, we formally extend the concept of counterexample, which has been proposed in model checking previously, and provide examples which demonstrate the need for such an extension. Moreover, we investigate into optimization issues for the problem of finding a repair, and present techniques which gain in some cases a considerable reduction of the search space for a repair. keywords: abductive theory revision, model checking, diagnosis and repair