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From: ok@cs.mu.oz.au (Richard O'Keefe)
Newsgroups: comp.lang.lisp
Subject: Re: Total ordering for Lisp objects ?
Summary: but see NU Prolog
Message-ID: <2101@munnari.oz.au>
Date: 14 Sep 89 07:18:54 GMT
References: <5896@lifia.imag.fr> <865@skye.ed.ac.uk> <2084@munnari.oz.au> <881@skye.ed.ac.uk>
Sender: news@cs.mu.oz.au
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In article <881@skye.ed.ac.uk>, jeff@aiai.uucp (Jeff Dalton) writes:
> But Prolog has something very like destructive assignment, namely
> variable instantiation.  For example, you might have a structure
> that contains an uninstantiated variable, and then its position
> in the total ordering will change after you instantiate the variable.

In NU-Prolog, termCompare(Order, Term_1, Term_2) "delays until Term_1
and Term_2 are instantiated enough for comparison to be made under the
standard ordering, that is, until any further instantiation would not
change the ordering already determined."  (NU-Prolog 1.3 manual, TR 86/10.)

Enough already.  Back to the regular "why doesn't the SNARK package work
in BELLMAN Lisp on a BEAVER-98" topic.