Default Logic Models of Certain Inheritance Systems with Exceptions

Article type: Research Article

Authors: Garlatti, Serge

Affiliations: Laboratoire I.A. et Systèmes Cognitifs, Ecole Nationale Supérieure des Telecommunications de Bretagne, ZI de Kernevent, BP 832, 29285 Brest Cedex, France, Tel.: (33) 98 00 14 53, Fax: (33) 98 00 12 82, E-mail: serge@enstb.enst-bretagne.fr

Abstract: Representation systems based on inheritance networks are founded on the hierarchical structure of knowledge. Such representation is composed of a set of objects and a set of is-a links between nodes. Objects are generally defined by means of a set of properties. An inheritance mechanism enables us to share properties across the hierarchy, called an inheritance graph. It is often difficult, even impossible to define classes by means of a set of necessary and sufficient conditions. For this reason, exceptions must be allowed and they induce nonmonotonic reasoning. Many researchers have used default logic to give them formal semantics and to define sound inferences. In this paper, we propose a survey of the different models of nonmonotonic inheritance systems by means of default logic. A comparison between default theories and inheritance mechanisms is made. In conclusion, the ability of default logic to take some inheritance mechanisms into account is discussed.

DOI: 10.3233/FI-1993-182-404

Journal: Fundamenta Informaticae, vol. 18, no. 2-4, pp. 129-149, 1993