Certification of Confluence Proofs using CeTA

TL;DR

CeTA is a certification tool originally for termination proofs, now extended to certify confluence and non-confluence proofs with minimal certificate information, enhancing trust in automated rewriting system proofs.

Contribution

The paper introduces CeTA's extension to certify confluence and non-confluence proofs, broadening its application beyond termination proofs.

Findings

Supports certification of confluence proofs

Requires minimal certificate information

Enhances trust in automated rewriting proofs

Abstract

CeTA was originally developed as a tool for certifying termination proofs which have to be provided as certificates in the CPF-format. Its soundness is proven as part of IsaFoR, the Isabelle Formalization of Rewriting. By now, CeTA can also be used for certifying confluence and non-confluence proofs. In this system description, we give a short overview on what kind of proofs are supported, and what information has to be given in the certificates. As we will see, only a small amount of information is required and so we hope that CSI will not stay the only confluence tool which can produce certificates.