Knowbel: a hybrid tool for building expert systems

Knowbel, an expert system tool that at one level supports representation and organization of concepts and on a second level offers a logic programming system that lets developers tailor an inference mechanism to a particular application, is discussed. Knowbel´s top level uses the Telos knowledge representation language to represent and organize the concepts describing the application; instead of a production-rule language, Telos uses an assertional sublanguage based on deductive database research. Instead of a procedural language, Knowbel´s second level uses the MRS (metareasoning system) logic programming system to customize the expert system´s search strategy for the task at hand. Knowbel´s system architecture and prototype implementation are described. Two prototype applications, an alarm-filtering component for the APACS project and an intelligent help system for computer users, are also discussed.<>