The XPRT Description System
This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. The author was sponsored by the Institute of International Education on an ITT-fellowship.
This paper introduces a frame-based description language and studies methods for reasoning about problems using knowledge expressed in the language. The system is based on the metaphor of a society of communicating experts and incorporates within this framework most of the currently known AI techniques, such as pattern-directed invocation, explicit control of reasoning, propagation of constraints, dependency recording, context mechanisms, message passing, conflict resolution, default reasoning, etc.