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Re: the idea of a 'reserved' vocabulary

From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
Date: Fri, 14 Jun 2002 17:36:59 +0100
Message-Id: <5.1.0.14.2.20020614172738.03a52730@joy.songbird.com>
To: Dan Connolly <connolly@w3.org>
Cc: patrick hayes <phayes@ai.uwf.edu>, w3c-rdfcore-wg@w3.org

At 08:15 AM 6/14/02 -0500, Dan Connolly wrote:
>Second, would somebody please show how this helps with layering?
>
>i.e. show how it relates to the example in...
>
># Layering OWL on RDF: the case for unasserted triples
>Jonathan Borden (Thu, May 30 2002)
>http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002May/0145.html

The example in the referenced document uses additional statements:

   owl:List rdf:type rdf:Unasserted .
   owl:first rdf:type rdf:Unasserted .
   owl:rest rdf:type rdf:Unasserted .
   owl:nil rdf:type rdf:Unasserted .

but Guha has explained that that approach is non-monotonic.

The revised proposal simply defines triples using certain URIs to be 
unasserted, regardless of any other triples that may appear in the graph, 
so there's no question that adding a new triple makes a truth out of a 
falsehood.

Referring to my suggestion, the properties used above as owl:List, 
owl:first, owl:rest, owl:nil would be given URIs of the form:

   http://www.w3.org/2002/06-rdf-unasserted#List
   http://www.w3.org/2002/06-rdf-unasserted#first
   http://www.w3.org/2002/06-rdf-unasserted#rest
   http://www.w3.org/2002/06-rdf-unasserted#nil

Actually, I don't think List and nil need to be given this unasserted 
treatment.

Indeed, in the case of nil, I think it may be a serious error, because 
there would be no meaning associated with statements like:

   ex:someResource ex:someListValuedProperty unasserted:nil .

#g


-------------------
Graham Klyne
<GK@NineByNine.org>
Received on Friday, 14 June 2002 12:51:00 EDT

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