ADavis%SRI-KL@sri-unix.UUCP (03/29/84)
From: Al Davis <ADavis at SRI-KL>
[Forwarded from the SRI-AI bboard by Laws@SRI-AI.]
Seminar
Friday, March 30
10:00 a.m. in the AI Conference Room
Fairchild AI Labs, 4001 Miranda Ave., Palo Alto
by
John S. Conery
University of Oregon
Title: The AND/OR Process Model for Parallel Interpretation of Logic
Programs.
Abstract: In contrast to the traditional depth first sequential process
tree search used for logic program evaluation, this talk presents the AND/OR
process model. It is a method for interpretation by a system of
asynchronous, independent processes that communicate only by messages.
The method makes it possible to exploit two distinct forms of
parallelism. OR parallelism is obtained from evaluating
nondeterministic choices in parallel. AND parallelism arises in the
execution of deterministic functions, such as matrix multiplication or
divide and conquer algorithms, that are inherently parallel. The two
forms of parallelism can be exploited at the same time. This means
AND parallelism can be applied to clauses that are composed of several
nondeterministic components, and it can recover from incorrect choices
in the solution of these components. In addition to defining parallel
computations, the model provides a more defined procedural semantics
for logic programs; that is, parallel interpreters based on this model
are able to generate answers to queries that cause standard
interpreters to go into an infinite loop. The interpretation method
is intended to form the theoretical framework of a highly parallel non
von Neumann computer architecture; the talk concludes with a
discussion of issues involved in implementing the abstract interpreter
on a multiprocessor.
al
Notes to visitors: Arrive at Fairchild between 9:45 and 10:00 and go
to the guard and tell him you are there to visit Al Davis at X4385.
They will call me and someone will come down and get you and haul you
off to the AI conference room.