Fast reasoning with external data on personal computers

Possible ways of speeding-up the inference cycle of inference engines capable of reasoning with external data are studied in this paper. The design and implementation of such inference engines on personal computers and PC-based workstations are illustrated by a description of FLEXIE, a PC-based inference engine. FLEXIE has been developed as an integral part of FLEX, a prototype real-time expert system shell for personal computers. The FLEX shell is briefly reviewed in the paper, and FLEXIE is examined in detail. A fast pattern-matcher, based on the RETE algorithm, is built into FLEXIE. During the pattern-matching phase, FLEXIE communicates with FLEXEN, the FLEX interface to the environment, in order to include external information into the reasoning process. The design of the pattern-matching algorithm makes it suitable for hardware implementation, which can make the pattern-matching process run considerably faster. An architecture for such a hardware pattern-matcher is proposed, and initial simulation results are presented. Two possibilities for concurrent implementation of the inference cycle are used in the design of the hardware pattern-matcher. The contribution of parallelism to the pattern-matching speed-up is also discussed. Simulation shows the overall speed-up to be more than an order of magnitude.