Typicality-based Revision for Handling Exceptions in Description Logics

We continue our investigation on how to revise a Description Logic knowledge base when detecting exceptions. Our approach relies on the methodology for debugging a Description Logic terminology, addressing the problem of diagnosing inconsistent ontologies by identifying a minimal subset of axioms responsible for an inconsistency. In the approach we propose, once the source of the inconsistency has been localized, the identified TBox inclusions are revised in order to obtain a consistent knowledge base including the detected exception. We define a revision operator whose aim is to replace inclusions of the form “Cs are Ds” with “typical Cs are Ds”, admitting the existence of exceptions, obtaining a knowledge base in the nonmonotonic logic ALCminT which corresponds to a notion of rational closure for Description Logics of typicality. We also describe an algorithm implementing such a revision operator.