Default inheritance reasoning in hybrid kl-one-style logics

Hybrid KL-ONE-style logics are knowledge rep-resentation formalisms of considerable applica-tive interest, as they are specifically oriented to the vast class of application domains that are describable by means of taxonomic organiza-tions of complex objects. In this paper we con-sider the problem of endowing such logics with capabilities for default inheritance reasoning, a kind of default reasoning that is specifically ori-ented to reasoning on taxonomies. The formal-ism that results from our work has a reasonable and simple behaviour when dealing with the in-terplay of defeasible and strict inheritance of properties of complex objects.