FORMAL DESCRIPTION AND VERIFICATION OF HYBRID RULE FRAME-BASED EXPERT-SYSTEMS/

A Hybrid Expert System combines multiple representation paradigms into a single integrated environment for modeling and reasoning of complic ated real world phenomena. For a Rule- and Frame-based integration, it models the problem domain using the concepts of Classes and Rules tog ether If Domain knowledge (concepts) is related by production rules an d frame hierarchy, then anomalies may arise among this knowledge (conc epts) due to the existence of two mutually independent formalism of re lations. A contribution is made in this paper to developing formal des cription techniques for the detection of anomalies attributed to the i ntegration of production rules with the inheritance of object properti es within the object hierarchy. The main idea is to convert the HES in to a State Controlled Coloured Petri Net (SCCPN) where the object hier archy, property inheritance and production rules are modelled as separ ated components in the same SCCPN. The detection and analysis of the a nomalies (i.e. Correctness, Consistency and Completeness) in the syste m are done by constructing and examining the reachability tree spanned by the knowledge inference. (C) 1997 Elsevier Science Ltd. All rights reserved.