Default Inheritance Reasoning in Hybrid KL-ONE-style Logics *

Hybrid KL-ONE-style logics are knowledge representation formalisms of considerable applicative interest, as they are specifically oriented to the vast class of application domains that are describable by means of taxonomic organizations of complex objects. In this paper we consider the problem of endowing such logics with capabilities for default inheritance reasoning, a kind of default reasoning that is specifically oriented to reasoning on taxonomies. The formalism that results from our work has a reasonable and simple behaviour when dealing with the interplay of defeasible and strict inheritance of properties of complex objects.