M.: Bounded model checking and induction: From refutation to verification

Abstract. We explore the combination of bounded model checking and induction for proving safety properties of infinite-state systems. In par-ticular, we define a general k-induction scheme and prove completeness thereof. A main characteristic of our methodology is that strengthened invariants are generated from failed k-induction proofs. This strengthen-ing step requires quantifier-elimination, and we propose a lazy quantifier-elimination procedure, which delays expensive computations of disjunc-tive normal forms when possible. The effectiveness of induction based on bounded model checking and invariant strengthening is demonstrated using infinite-state systems ranging from communication protocols to timed automata and (linear) hybrid automata.