Uniform Interpolants in EUF: Algorithms using DAG-representations
Abstract
The concept of uniform interpolant for a quantifier-free formula from a given formula with a list of symbols, while well-known in the logic literature, has been unknown to the formal methods and automated reasoning community for a long time. This concept is precisely defined. Two algorithms for computing quantifier-free uniform interpolants in the theory of equality over uninterpreted symbols (EUF) endowed with a list of symbols to be eliminated are proposed. The first algorithm is non-deterministic and generates a uniform interpolant expressed as a disjunction of conjunctions of literals, whereas the second algorithm gives a compact representation of a uniform interpolant as a conjunction of Horn clauses. Both algorithms exploit efficient dedicated DAG representations of terms. Correctness and completeness proofs are supplied, using arguments combining rewrite techniques with model theory.
Cite
@article{arxiv.2002.09784,
title = {Uniform Interpolants in EUF: Algorithms using DAG-representations},
author = {Silvio Ghilardi and Alessandro Gianola and Deepak Kapur},
journal= {arXiv preprint arXiv:2002.09784},
year = {2023}
}