Verified Model Checking for Conjunctive Positive Logic

Data Refinement for Verified Model-Checking Algorithms in Isabelle/HOL

Our goal is to verify model-checking algorithms with Isabelle/HOL. When regarding such algorithms on an abstract level, they often use nondeterminism like ”take an element from this set”. Which element is actually taken depends on the concrete implementation of the set. When formalizing these algorithms, one has to either fix the concrete implementation for the correctness proof, or describe th...

Temporal Logic Model Checking

ion reduces the state space by removing irrelevant features of a Kripke structure. Given a Kripke structure K, an abstraction is a Kripke structure K̂ such that K̂ is significantly smaller than K, and K̂ preserves a useful class of specifications for K. Consequently, the expensive task of model checking K can be reduced to the more feasible task of model checking K̂. We know from above that in orde...

Model Checking for Timed Logic Processes

Coverage Metrics for Temporal Logic Model Checking

In formal verification, we verify that a system is correct with respect to a specification. Even when the system is proven to be correct, there is still a question of how complete the specification is, and whether it really covers all the behaviors of the system. In this paper we study coverage metrics for model checking. Coverage metrics are based on modifications we apply to the system in ord...

Logic Programming Optimizations for Faster Model Checking

Over the last three years, we have showed that logic programming with tabulation can be used to construct eÆcient model checkers [RRR97, CDD98, DDR99]. In particular, we have developed XMC [RRS00], a model checker which veri es properties written in the alternation-free fragment of the modal mu-calculus [Koz83] for systems speci ed in XL, an extension of value-passing CCS [Mil89]. The XMC syste...