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U.S. Department of Energy
Office of Scientific and Technical Information

Parallel logic programming and ZMOB and parallel systems software and hardware. Final report

Technical Report ·
OSTI ID:5542474

Under the current grant, parallel hardware and systems software implemented on ZMOB in the previous year underwent extensive testing. A parallel problem-solving system, PRISM (Parallel Inference System) implemented on the VAX/11-780 in the previous year was implemented on the PYRAMID and SUN machines. The initial version of PRISM uses a simulation of the ZMOB hardware, and was fully tested and debugged. Experimental testing of PRISM on the simulated system was undertaken in the current year. In addition, several enhancements were made to PRISM to permit experimental analyses to be made, and to incorporate additional features to take full advantage of parallelism in a problem-solving environment. The tracing and statistical gathering packages were extended. An AND-parallelism capability was added to achieve a second version of the PRISM system, and other features were added to the system to more fully exploit parallelism. A constraint solving machine was integrated with PRISM. In addition to the above, a general method to permit informative answers to be presented to a user was developed. Theoretical results were obtained for circumscription and a method for computing in protected circumscription, using Horn clauses, was developed. In the area of systems hardware and software, the ZMOB processor is now fully functional and in everyday use with 128 processors.

Research Organization:
Maryland Univ., College Park (USA). Dept. of Computer Science
OSTI ID:
5542474
Report Number(s):
AD-A-186300/0/XAB
Country of Publication:
United States
Language:
English