This research investigates the use of parallel computation systems (systems of many computing elements operating simultaneously) for knowledge representation, reasoning, and problem solving in large knowledge based systems. Experimental studies of computer performance are coupled with theoretical analysis of the algorithms involved. The importance of this research is that it significantly advances the usefulness of parallel computing power for real knowledge based applications. This award is being funded as one of the 1988 Research Initiation Awards for outstanding new investigators in the Computer and Information Science and Engineering (CISE) Directorate.