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Re: [SWC] RIF & OWL compatibility

From: Michael Kifer <kifer@cs.sunysb.edu>
Date: Thu, 12 Jan 2006 11:06:52 -0500
To: "Gerd Wagner" <wagnerg@tu-cottbus.de>
Cc: "'Enrico Franconi'" <franconi@inf.unibz.it>, "'Jos de Bruijn'" <jos.debruijn@deri.org>, public-rif-wg@w3.org
Message-Id: <20060112160652.A1310CB968@kiferserv.kiferhome.com>

"Gerd Wagner" <wagnerg@tu-cottbus.de> wrote:
> Enrico and Jos,
> yes, the issue of existential information is interesting
> (and also in the field of databases there is no consensus
> about null values being a good idea or not), but is it 
> really an urgent issue for RIF? 
> Some form of null values (or "blank nodes" or skolem 
> constants/terms) may be useful, but probably not needed 
> in phase 1. Do you know of any non-experimental (if not 
> commercial) rule system that supports existential 
> information?
> The differences between a constructive LP-style 
> interpretation of the existential quantifier and 
> the non-consructive classical logic and DL-style 
> interpretation seem to be even less relevant for
> RIF than the issue itself.
> -Gerd

Exactly. From talking to a number of people with real-world RDF experience,
I get the impression that b-nodes are used to refer to individuals when it
is too inconvenient to give them explicit names. This is just Scolemization.

Does anybody have *real-world* RDF experience with cases where truly
existential semantics of b-nodes is used?

Received on Thursday, 12 January 2006 16:07:11 UTC

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