Re: Behavior of assert and retract

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Article #2720

#2720

From: F.W.G.M. de Bruyn Philips CAD Ce...
Date: Thu, 16 Jul 1987 11:29

25 lines
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In article <19702@ucbvax.BERKELEY.EDU> citrin@ji.Berkeley.EDU.UUCP (Wayne Citrin) writes:
>clauses of needs_visiting/1 than when it can.  I favor fixing the visible
>clauses at the time that the choice point is created since this seems to make
>it easier to make informal 'assertions' about the behavior of the code
>(in other words, to understand what's going on).

I don't think this should be  used as an  argument in favour of fixing
the set of  branch destinations in  a choice point  at  the moment  of
calling.  Facilities for  hypothetical  reasoning (that's what's being
asked for) should be implemented through a partitioned clause-base (in
other words: modularity).

It would be interesting to learn from Fernando Perreira (C-prolog) and
Richard  o'Keefe (ok@quintus.uucp) what arguments  pro  and  con  they
weighed when opting for this route.

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Path: arc1-ca.pugleaf.net!utzoo!mnetor!uunet!seismo!mcvax!philmds!philtis!debruyn
From: debruyn@philtis.UUCP (F.W.G.M. de Bruyn @ Philips CAD Centr)
Newsgroups: comp.lang.prolog
Subject: Re: Behavior of assert and retract
Message-ID: <237@philtis.UUCP>
Date: Thu, 16-Jul-87 07:29:49 EDT
Article-I.D.: philtis.237
Posted: Thu Jul 16 07:29:49 1987
Date-Received: Sat, 18-Jul-87 05:58:42 EDT
References: <3287@bigburd.PRC.Unisys.COM> <19702@ucbvax.BERKELEY.EDU>
Reply-To: debruyn@philtis.UUCP
Organization: Philips - CAD Centre, Eindhoven, The Netherlands
Lines: 25
Keywords: backtracking to retract

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