Extended Abstract: Combining a Logical Framework with an RUP Checker for SMT Proofs

We describe work in progress on a new approach, and associated tools, for checking proofs produced by SMT solvers. The approach extends our previous work on LFSC (“Logical Framework with Side Conditions”), a meta-language in which different proof systems for different SMT solvers can be declaratively specified. In this paper, we show how the LFSC proof checker can delegate the checking of propositional inferences (within a proof of an SMT formula) to a propositional proof checker clcheck based on Reverse Unit Propagation (RUP). This approach shows promising improvements in proof size and proof checking time for benchmark proofs produced by the clsat QF IDL solver. We also discuss work in progress to replace clcheck with a different RUP checker we are developing called vercheck, whose soundness we are in the process of statically verifying.