EPR-based k-induction with Counterexample Guided Abstraction Refinement

Abstract

In recent years it was proposed to encode bounded model checking (BMC) into the effectively propositional fragment of first-order logic (EPR). The EPR fragment can provide for a succinct representation of the problem and facilitate reasoning at a higher level. In this paper we present an extension of the EPR-based bounded model checking with k-induction which can be used to prove safety properties of systems over unbounded runs. We present a novel abstraction-refinement approach based on unsatisfiable cores and models (UCM) for BMC and k-induction in the EPR setting. We have implemented UCM refinements for EPR-based BMC and k-induction in a first-order automated theorem prover iProver. We also extended iProver with the AIGER format and evaluated it over the HWMCC'14 competition benchmarks. The experimental results are encouraging. We show that a number of AIG problems can be verified until deeper bounds with the EPR-based model checking.

Do Portfolio Solvers Harm?

“…If problem domains become more specific, such as in dedicated applications, or single problems become difficult, then SS-portfolio solvers are typically not a preferred option. For example, see the hardware model checking competition [15], complete reasoning in large ontologies [26], or reasoning in the context of complexity management [12]. Now combining all of the above, SS-portfolio solvers are mainly useful for a particular kind of competition but not from a scientific perspective.…”