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classification inferences based on owl:disjointWith

From: Steve Gollery <sgollery@cadrc.calpoly.edu>
Date: Tue, 11 Jan 2005 09:59:11 -0800
Message-ID: <41E413EF.4020000@cadrc.calpoly.edu>
To: www-rdf-interest@w3.org

I'm using Jena with Racer as the DIG reasoner, using a test program 
based on the "Extended example" at 

I have an ontology that imports foaf. After I load the ontology, I list 
the OWL classes using OntModel.listClasses. The foaf classes don't show 
up on the list, although they do appear when I list all the statements 
with predicate "rdf:type" and object "rdfs:Class." It looks like Racer 
is not inferring that the foaf classes are OWL classes, even though they 
are defined like this:

   <rdfs:Class rdf:about="http://xmlns.com/foaf/0.1/Document" 
rdfs:label="Document" rdfs:comment="A document.">
     <rdfs:subClassOf rdf:resource="http://xmlns.com/wordnet/1.6/Document"/>
     <rdfs:isDefinedBy rdf:resource="http://xmlns.com/foaf/0.1/"/>
     <owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Person"/>
     <owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Project"/>

Since the domain and range of owl:disjointWith is owl:Class, I would 
expect that an inference engine would classify foaf:Document as an 
owl:Class even though the ontology states that foaf:Document is an 

Am I wrong about that?

Steven Gollery
Received on Tuesday, 11 January 2005 20:54:23 UTC

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