On the Completeness of Selective Unification in Concolic Testing of Logic Programs

TL;DR

This paper investigates the completeness of selective unification in concolic testing for logic programs, identifying issues with existing algorithms and proposing alternatives to achieve soundness and completeness.

Contribution

It reveals the incompleteness of current selective unification algorithms and proposes new methods to ensure soundness and completeness in concolic testing of logic programs.

Findings

Existing algorithms are incomplete for selective unification.

Proposed alternative algorithms improve soundness and completeness.

Enhances the reliability of concolic testing in logic programming.

Abstract

Concolic testing is a popular dynamic validation technique that can be used for both model checking and automatic test case generation. We have recently introduced concolic testing in the context of logic programming. In contrast to previous approaches, the key ingredient in this setting is a technique to generate appropriate run-time goals by considering all possible ways an atom can unify with the heads of some program clauses. This is called "selective" unification. In this paper, we show that the existing algorithm is not complete and explore different alternatives in order to have a sound and complete algorithm for selective unification.