Identifying Overly Restrictive Matching Patterns in SMT-based Program Verifiers (extended version)

Universal quantifiers occur frequently in proof obligations produced by program verifiers, for instance, to axiomatize uninterpreted functions and statically express properties of arrays. SMT-based verifiers typically reason about them via E-matching, an SMT algorithm that requires syntactic matching patterns guide the quantifier instantiations. Devising good is challenging. In particular, overly restrictive may lead spurious verification errors if needed a are not instantiated; they also conceal unsoundness caused inconsistent axiomatizations. this paper, we present first technique identifies helps users developers remedy effects patterns. We designed novel synthesize missing triggering terms required complete unsatisfiability proofs E-matching. Tool can use information refine their prevent similar errors, or fix detected unsoundness.