A new semantics for overriding in description logics

Many modern applications of description logics (DLs, for short), such as biomedical ontologies and semantic web policies, provide fresh motivations for extending DLs with nonmonotonic inferences—a topic that has attracted a significant amount of attention along the years. Despite this, nonmonotonic inferences are not yet supported by DL technology due to a number of issues related to expressiveness, computational complexity, and optimizations. This paper contributes to the practical support of nonmonotonic inferences in description logics by introducing a new semantics expressly designed to address knowledge engineering needs. This formalism has appealing expressiveness, enjoys nice computational properties, and constitutes an interesting solution to an ample class of application needs. The formalism is validated through extensive comparison with the other nonmonotonic DLs, and systematic scalability tests. The test case generator and its novel validation methodology constitute a further contribution of this paper.