Recycling Algebraic Proof Certificates

Abstract: Proof certificates can be used to validate the correctness of algebraic derivations. However, in practice, we frequently observed that the exact same proof steps are repeated for different sets of variables, which leads to unnecessarily large proofs. To overcome this issue we extend the existing Practical Algebraic Calculus with linear combinations (LPAC) with two new proof rules that allow us to capture and reuse parts of the proof to derive a more condensed proof certificate. We integrate these rules into the proof checker Pacheck 2.0. Our experimental results demonstrate that the proposed extension helps to reduce both proof size and verification time.