Towards Relational Contextual Equality Saturation

Abstract: Equality saturation is a powerful technique for program optimization. Contextual equality saturation extends this to support rewrite rules that are conditioned on where a term appears in an expression. Existing work has brought contextual reasoning to egg; in this paper, we share our ongoing work to extend this to relational equality saturation in egglog. We summarize the existing approaches to contextual equality saturation, outline its main applications, and identify key challenges in combining this approach with relational models.