A case study of parallel execution of a rule-based expert system

We report on a case study of the potentials for parallel execution of the inference engine of EMYCIN, a rule-based expert system. Multilisp, which supports parallel execution of tasks by means of thefuture construct, is used to implement the parallel version of the backwards-chaining inference engine. The study uses explicit specification of parallel execution and synchronization to attain parallel execution. It suggests some general techniques for obtaining parallel execution in expert systems and other applications.