Re: expressing scope of negation of failure (wasRe: Open Worlds, Distribution, Delegation, Federation, Logic, NI )

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Date: Wed, 7 Mar 2001 08:34:44 -0500 (EST)
 From: Gustaf Neumann <neumann@wu-wien.ac.at>
 To: Graham Klyne <GK@ninebynine.org>, "Tim Berners-Lee" <timbl@w3.org>
 Cc: <www-rdf-interest@w3.org>
 In-Reply-To: <5.0.2.1.2.20010307120436.03da5620@joy.songbird.com>
 Message-Id: <0103071434100D.06279@mohegan.wu-wien.ac.at>
 Subject: Re: expressing scope of negation of failure (wasRe: Open Worlds, Distribution, Delegation, Federation, Logic, NI )

On Wednesday 07 March 2001 13:13, Graham Klyne wrote:
> I think this is an excellent example of why we should not rush to put full
> first order logic into the core of RDF, but rather to build it, where
> needed, in a framework constructed on RDF.
>
> I have a sense that for some applications, like this, there is much that
> can be achieved without full FOL.  And there may be other ways of dealing
> with things normally handled by negation.

i do fully agree about this statement, it is definitely not a good idea
right now to start to discuss different kind of negation semantics, 
stable model semantics, modal logics, and other controversial and - i would say -
application specific problems. It is not clear to me, up to which point the 
closed world assumption (basis for negation as failure) makes sense in the 
context of RDF and distributed metadata.

my strong recommendation is to stick with horn clauses and - if possible -
pure datalog in any core RDF* design. 

best regards
-gustaf

Received on Thursday, 8 March 2001 07:45:53 UTC