Rehabilitating equivalent mutants as static anomaly detectors in software artifacts

In mutation analysis a mutant is said equivalent if it leaves the semantics of the program or the model unchanged. Equivalent mutants are usually seen as an inconvenience; for example, in software testing they cannot be detected by a test and, therefore, they fictitiously reduce the mutation score of a test suite. In this paper, instead, equivalent mutants are seen as an opportunity, since they can be used to find some static anomalies of software artifacts, i.e., anomalies that can be removed without affecting the artifact semantics. The proposal is applicable to different kinds of software artifacts as source code, Boolean expressions, and feature models.