Constraint-Based Algorithm for Computing Temporal Invariants

Abstract

Automatically identified invariants are an important part of reductions of state-space reachability problems to SAT and related formalisms as a method of pruning the search space. No general algorithms for computing temporal invariants have been proposed before. Earlier algorithms restrict to unconditional actions and at-most-one invariants. We propose a powerful inductive algorithm for computing invariants for timed systems, showing that a wide range of timed modeling languages can be handled uniformly. The algorithm reduces the computation of timed invariants to a sequence of temporal logic consistency tests.