Prism: a Testbed for Parallel Control

A Parallel Inference System for Problem Solving (PRISM) has been designed and implemented. The system provides a general experimental tool for the construction of large artificial intelligence problem solvers. In this paper we present some of the basic facilities for controlling parallelism and inference provided by the system and present experimental data on the use of these facilities. The experiments concern the functionality of the processing elements, the use of heuristics to reduce the search space at run-time, and the use of message passing to distribute tasks in distributed memory parallel machines. The experiments were performed using PRISM on two parallel machines - a one-hundred node shared memory BBN Butterfly, and a 16 node message passing machine.