Combining Classification and Nonmonotonic Inheritance Reasoning: A First Step

The formal analysis of semantic networks and frame systems led to the development of nonmonotonic inheritance networks and terminological logics. While nonmonotonic inheritance networks formalize the notion of default inheritance of typical properties, terminological logics formalize the notion of defining concepts and reasoning about definitions. Although it seems to be desirable to (re-)unify the two approaches, such an attempt has not been made until now. In this paper, we will make a first step into this direction by specifying a nonmonotonic extension of a simple terminological logic.