Clausal resolution for CTL

In this paper we consider proof techniques for branching-time temporal logics. While a considerable amount of research has been carried out regarding the relationship between finite automata and such logics, practical proof techniques for such logics have received relatively little attention. Recently, however, several applications requiring refined proof methods for branching-time temporal logics have appeared, most notably the specification and verification of multi-agent systems. Thus, here we extend our clausal resolution method for linear-time temporal logics to a branching-time framework, in particular to the powerful CTL* logic. The key elements of the resolution method, namely the normal form, the concept of step resolution and a novel temporal resolution rule, are introduced, justified, and applied.