Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!bradley
From: bradley@cs.utexas.edu (Bradley L. Richards)
Newsgroups: comp.lang.prolog
Subject: Re: '->' operator
Message-ID: <16491@cs.utexas.edu>
Date: 4 Jan 91 04:58:18 GMT
References: <291@valverde.cs.utexas.edu> <1991Jan4.030918.24996@athena.cs.uga.edu>
Organization: Dept of Computer Sciences, UTexas, Austin
Lines: 23

In article <1991Jan4.030918.24996@athena.cs.uga.edu> mcovingt@athena.cs.uga.edu (Michael A. Covington) writes:
>  Further, the -> operator is not intended to be an encoding of anything
>  in classical logic. It is a Pascal-like, *procedural* if-then-else
>  construct, designed to make it easier to express algorithms.
>  The equivalent of classical logic "implies" is :- .

Ah, but if '->' is intended to be an implementation of the procedural
if-then-else (or, in the case I'm concerned with, if-then) then it
should still succeed if the condition is false.  After all, procedurally
execution will continue following an if statement whether or not the
condition in the if was true.

So either under the logical interpretation or under the procedural one
it seems to me that the Quintus '->' works improperly.

Bradley

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 Bradley L. Richards             "The abandonment of formal mathematics
 bradley@cs.utexas.edu           is an extremely popular thing to do in
 uucp:  cs.utexas.edu!bradley    computer science."
                                                    Dr. Robert Boyer, NACLP-90
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