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Re: Guide: draft of Oct 31

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 31 Oct 2002 17:23:08 -0500 (EST)
Message-Id: <20021031.172308.92423487.pfps@research.bell-labs.com>
To: michael.smith@eds.com
Cc: www-webont-wg@w3.org

From: "Smith, Michael K" <michael.smith@eds.com>
Subject: RE: Guide: draft of Oct 31
Date: Thu, 31 Oct 2002 16:04:57 -0600

> I will change the Guide syntax.  As OWL this is clearly wrong.
> 
> In terms of RDF, how could it be malformed?  I thought a class 
> could be a property could be an individual.  For example, in
> 
> <rdf:RDF
>   xmlns     = "http://www.example.org/test#"
>   xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>   xmlns:rdfs= "http://www.w3.org/2000/01/rdf-schema#">
> 
>   <rdf:Class rdf:ID="C1" /> 
>   <rdf:Class rdf:ID="C2" /> 
> 
>   <rdf:Description rdf:ID="I2">
>     <C2 rdf:resource="#I1" />
>   </rdf:Description>
> 
> </rdf:RDF>
> 
> The occurence of C2 in the defintion of I2 would just be treated 
> as a property.  Right?

Yes, but the RDF/XML has to encode n-triples, and n-triples need three
things, a subject, a predicate, and an object.  The above results in
something like

	C1 rdf:type rdf:Class .  (from one of the RDF/XML abbreviations)
	C2 rdf:type rdf:Class .  (from one of the RDF/XML abbreviations)
	I2 C2 I1 .

RDF/XML like

 <rdf:RDF
   xmlns     = "http://www.example.org/test#"
   xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:rdfs= "http://www.w3.org/2000/01/rdf-schema#">
 
   <rdf:Class rdf:ID="C1" /> 
   <rdf:Class rdf:ID="C2" /> 
 
   <rdf:Description rdf:ID="I2">
     <C2 />
   </rdf:Description>
 
 </rdf:RDF>

results in, to me,

	C1 rdf:type rdf:Class .  (from one of the RDF/XML abbreviations)
	C2 rdf:type rdf:Class .  (from one of the RDF/XML abbreviations)
	I2 C2 .

where the last triple is missing its object.  Dan thinks that an implicit
object of "" is generated, but I don't see how that can come out of the
RDF/XML syntax.

peter
Received on Thursday, 31 October 2002 17:23:16 GMT

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