Why Not? Explaining Missing Entailments with Evee (Technical Report)

Understanding logical entailments derived by a description logic reasoner is not always straight-forward for ontology users. For this reason, various methods for explaining entailments using justifications and proofs have been developed and implemented as plug-ins for the ontology editor Prot'eg'e. However, when the user expects a missing consequence to hold, it is equally important to explain why it does not follow from the ontology. In this paper, we describe a new version of rm Escriptsize VEE, a Prot'eg'e plugin that now also provides explanations for missing consequences, via existing and new techniques based on abduction and counterexamples.