Incrementally Computing Minimal Unsatisfiable Cores of QBFs via a Clause Group Solver API

TL;DR

This paper introduces a new API for incremental QBF solving that simplifies the computation of minimal unsatisfiable cores by managing clause groups, demonstrated through implementation and experimental results.

Contribution

The paper presents a novel clause group API for incremental QBF solving, enabling efficient MUC computation and seamless integration with other tools.

Findings

API simplifies incremental QBF solving process

First experimental evaluation of MUC computation using the API

Demonstrates improved integration and usability in tools

Abstract

We consider the incremental computation of minimal unsatisfiable cores (MUCs) of QBFs. To this end, we equipped our incremental QBF solver DepQBF with a novel API to allow for incremental solving based on clause groups. A clause group is a set of clauses which is incrementally added to or removed from a previously solved QBF. Our implementation of the novel API is related to incremental SAT solving based on selector variables and assumptions. However, the API entirely hides selector variables and assumptions from the user, which facilitates the integration of DepQBF in other tools. We present implementation details and, for the first time, report on experiments related to the computation of MUCs of QBFs using DepQBF's novel clause group API.