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Re: Open Issues: DR scope

From: Stasinos Konstantopoulos <konstant@iit.demokritos.gr>
Date: Thu, 6 Dec 2007 14:01:02 +0200
To: public-powderwg@w3.org
Message-ID: <20071206120102.GE3561@iit.demokritos.gr>


There's multiple ways to formulate in OWL the same abstract logical
formula, so both formulations (Kevin's and Andrea's) are perfectly valid
OWL fragments saying exactly the same thing. There's a lot more like
these two, and, in more complex cases, there isn't going be any
minimal-verbose ordering between them.

I haven't checked this, but I think that Andrea's more verbose
formulation is due to some Protege normalization. (Andrea?)

s


On Wed Dec  5 13:33:13 2007 Smith, Kevin, VF-Group said:

> 
> Hi Andrea,
> 
> What puzzles me is the need for owl:equivalentClass, and rdfs:subClassOf
> (without an rdf:resource). My (admittedly poor) understanding was that
> using equivalentClass you would have:
> 
> 1  <owl:Class rdf:ID="ResourceOnExampleDotOrg">
> 2    <owl:equivalentClass>
> 3        <owl:Restriction>
> 4            <owl:onProperty rdf:resource="&wdr;includeHost" />
> 5            <owl:hasValue>example.org</owl:hasValue>
> 6          </owl:Restriction>
> 7   </owl:equivalentClass>
> 8 </owl:Class> 
> 
> (ref [1])
> 
> ...and that if you used subClassOf you would do something like (note
> insertion of rdf:ID="AllResources"):
> 
> 1  <owl:Class rdf:ID="ResourceOnExampleDotOrg">
> 4    <rdfs:subClassOf rdf:ID="AllResources">
> 5       <owl:Restriction>
> 6         <owl:onProperty rdf:resource="&wdr;includeHost" />
> 7          <owl:hasValue>example.org</owl:hasValue>
> 8         </owl:Restriction>
> 9    </rdfs:subClassOf>
> 12 </owl:Class>
> 
> (ref [2])
> 
> I'm sure your example is correct, I'm just not sure why - please could
> you help my understanding :)
> 
> Cheers
> Kevin
> 
> [1] http://www.w3.org/TR/2004/REC-owl-guide-20040210/#equivalentClass1
> [2]
> http://www.w3.org/TR/2004/REC-owl-guide-20040210/#DefiningSimpleClasses
> 
>  
> 
> -----Original Message-----
> From: public-powderwg-request@w3.org
> [mailto:public-powderwg-request@w3.org] On Behalf Of Andrea Perego
> Sent: 05 December 2007 08:36
> To: Public POWDER
> Subject: Open Issues: DR scope
> 
> 
> I would like again to ask for feedback about an issue which must be
> urgently solved, that is, how the scope of a DR is defined.
> 
> The current solution is the following:
> 
> 1  <owl:Class rdf:ID="ResourceOnExampleDotOrg">
> 2    <owl:equivalentClass>
> 3      <owl:Class>
> 4        <rdfs:subClassOf>
> 5          <owl:Restriction>
> 6            <owl:onProperty rdf:resource="&wdr;includeHost" />
> 7            <owl:hasValue>example.org</owl:hasValue>
> 8          </owl:Restriction>
> 9        </rdfs:subClassOf>
> 10     </owl:Class>
> 11   </owl:equivalentClass>
> 12 </owl:Class>
> 
> which literally means "all the resources having a URI host component
> ending with example.org" (i.e., "all the resources hosted by
> *.example.org").
> 
> So, the question is: does anybody agree that this the correct way to
> define a DR scope? If it isn't, which are the alternative solutions?
> 
> Andrea
> 
> 
> 
> 
> 
> 
> 
> 
Received on Thursday, 6 December 2007 12:01:25 GMT

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