Article View: comp.lang.prolog
Article #572Re: Fun. vs. Logic
From: Bradley L. Richards
Date: Wed, 13 Dec 1989 17:37
Date: Wed, 13 Dec 1989 17:37
19 lines
1359 bytes
1359 bytes
In article <11500020@hpldola.HP.COM>, patch@hpldola.HP.COM (Pat Chkoreff) writes:
>>
>> Negation worries me. A language feature should either be essential for
>> computation, or defined in terms of something that is. Negation is NOT
>> essential for computation, so I HOPE that it can be defined in terms of pure
>> Horn clauses, which are. Is there an effective procedure for removing
I know you've already gotten a lengthy response on eliminating negation, but
I think one quick additional note is in order. While it's true that
negation is unnecessary when computing in infinite domains (since positive
programs possess the full power of recursive function theory), this is
*not* true when computing in finite domains. If you are computing over
the domain, say, of citizens in Hoboken, then the ability to say
Stranger(Who) :- not citizen(Who)
in fact gives you a power you cannot duplicate without negation.
brad
Technical Details
Message-ID:
<438@ghidrah.cs.utexas.edu>Path:
arc1-ca.pugleaf.net!utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!bradleyReferences:
<11500018@hpldola.HP.COM> <11500020@hpldola.HP.COM> <2221@cs-spool.calgary.UUCP>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!bradley From: bradley@cs.utexas.edu (Bradley L. Richards) Newsgroups: comp.lang.prolog Subject: Re: Fun. vs. Logic Message-ID: <438@ghidrah.cs.utexas.edu> Date: 13 Dec 89 17:37:16 GMT References: <11500018@hpldola.HP.COM> <11500020@hpldola.HP.COM> <2221@cs-spool.calgary.UUCP> Organization: U. Texas CS Dept., Austin, Texas Lines: 19