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From: narain@randvax.UUCP (Sanjai Narain)
Newsgroups: comp.lang.prolog
Subject: Re: Why is bagof so slow?
Keywords: bagof, setof
Message-ID: <2559@randvax.UUCP>
Date: 29 May 90 21:57:45 GMT
References: <2556@randvax.UUCP> <3086@goanna.cs.rmit.oz.au>
Organization: Rand Corp., Santa Monica, Ca.
Lines: 17


I thank Alain Callebaut and Richard O'Keefe for quite useful answers to my
query about bagof.  The problem arose in the implementation of a
simulation technique in Prolog.  A model consists of causality rules,
roughly of the form:

	A causes B if C

Given that an event E has occurred, one needs to compute the set of
all F such that E causes F.

It turns out that in important cases the use of setof (or bagof) can
be eliminated. This has yielded a speedup of 20 for our current model.

Regards.

Sanjai