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Re: Equivalent Classes in OWL

From: Pascal Hitzler <hitzler@aifb.uni-karlsruhe.de>
Date: Tue, 18 Jul 2006 09:37:33 +0200
Message-ID: <44BC8FBD.1000408@aifb.uni-karlsruhe.de>
To: Luke Steller <Luke.Steller@infotech.monash.edu.au>
CC: public-owl-dev@w3.org, Denny Vrandecic <dvr@aifb.uni-karlsruhe.de>
Due to the domain of isHardWorking, both Quokka and Koalas are Persons. 
Since they are also Marsupials, you get a contradiction, i.e. Quokka and 
Koala must both be equal to owl:Nothing. Hence, KoalaWithPhD is also 
equal to owl:Nothing.

If you are familiar with DL syntax - I find it much more readable for 
analysing such things. The attached pdf was created with "KAON2 OWL 
Tools" (http://owltools.ontoware.org/).

Pascal.


Luke Steller schrieb:
> 
> Hello,
> 
> I have the following OWL ontology, which I am running on the Pellet
> reasoner. Can anyone tell me, why when i ask for a list of equivalent
> classes to KoalaWithPhD - that both Koala and Quokka are returned. I
> cant figure out the reason.
> 
> It has something to do with the isHardWorking property having the
> domain Person, which is disjoint with Marsupials - and both Quokka and
> Koala are subclasses of Marsupials.
> 
> ----------------------
> 
> 
> <?xml version="1.0"?>
> <rdf:RDF
>    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>    xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
>    xmlns:owl="http://www.w3.org/2002/07/owl#"
>    xmlns="http://protege.stanford.edu/plugins/owl/owl-library/koala.owl#"
>  xml:base="http://protege.stanford.edu/plugins/owl/owl-library/koala.owl">
>  <owl:Ontology rdf:about=""/>
> 
>  <owl:Class rdf:ID="Marsupials">
>    <owl:disjointWith>
>      <owl:Class rdf:about="#Person"/>
>    </owl:disjointWith>
>  </owl:Class>
> 
>  <owl:Class rdf:ID="KoalaWithPhD">
>    <owl:versionInfo>1.2</owl:versionInfo>
>    <owl:equivalentClass>
>      <owl:Class>
>        <owl:intersectionOf rdf:parseType="Collection">
>          <owl:Restriction>
>            <owl:hasValue>
>              <Degree rdf:ID="PhD"/>
>            </owl:hasValue>
>            <owl:onProperty>
>              <owl:ObjectProperty rdf:about="#hasDegree"/>
>            </owl:onProperty>
>          </owl:Restriction>
> 
>          <owl:Class rdf:about="#Koala"/>
>        </owl:intersectionOf>
>      </owl:Class>
>    </owl:equivalentClass>
>  </owl:Class>
> 
>  <owl:Class rdf:ID="Koala">
>    <rdfs:subClassOf>
>      <owl:Restriction>
>        <owl:hasValue 
> rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean"
>        >false</owl:hasValue>
>        <owl:onProperty>
>          <owl:DatatypeProperty rdf:about="#isHardWorking"/>
>        </owl:onProperty>
>      </owl:Restriction>
>    </rdfs:subClassOf>
>    <rdfs:subClassOf rdf:resource="#Marsupials"/>
>  </owl:Class>
> 
>  <owl:Class rdf:ID="Quokka">
>    <rdfs:subClassOf>
>      <owl:Restriction>
>        <owl:hasValue 
> rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean"
>        >true</owl:hasValue>
>        <owl:onProperty>
>          <owl:DatatypeProperty rdf:about="#isHardWorking"/>
>        </owl:onProperty>
>      </owl:Restriction>
>    </rdfs:subClassOf>
>   <rdfs:subClassOf rdf:resource="#Marsupials"/>
>  </owl:Class>
> 
>  <owl:Class rdf:ID="Degree"/>
> 
>  <owl:Class rdf:ID="Person">
>    <owl:disjointWith rdf:resource="#Marsupials"/>
>  </owl:Class>
> 
>  <owl:ObjectProperty rdf:ID="hasDegree">
>    <rdfs:domain rdf:resource="#Person"/>
>    <rdfs:range rdf:resource="#Degree"/>
>  </owl:ObjectProperty>
> 
>  <owl:DatatypeProperty rdf:ID="isHardWorking">
>    <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#boolean"/>
>    <rdfs:domain rdf:resource="#Person"/>
>  </owl:DatatypeProperty>
> 
> </rdf:RDF>
> 
> 
> 
> 
> ----------------------
> 
> Any comments would be greatly appreciated!
> 
> Many thanks,
> Luke
> 
> PhD Student
> Monash University
> Australia
> 

-- 
Dr. habil. Pascal Hitzler
Institute AIFB, University of Karlsruhe, 76128 Karlsruhe
email: hitzler@aifb.uni-karlsruhe.de    fax: +49 721 608 6580
web:   http://www.pascal-hitzler.de   phone: +49 721 608 4751
        http://www.neural-symbolic.org


Received on Tuesday, 18 July 2006 08:13:02 GMT

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