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RE: classification inferences based on owl:disjointWith

From: Geoff Chappell <geoff@sover.net>
Date: Wed, 12 Jan 2005 09:02:38 -0500
To: "'Steve Gollery'" <sgollery@cadrc.calpoly.edu>
Cc: <www-rdf-interest@w3.org>
Message-ID: <000001c4f8af$60da48e0$6401a8c0@gsclaptop>

> -----Original Message-----
> From: www-rdf-interest-request@w3.org [mailto:www-rdf-interest-
> request@w3.org] On Behalf Of Steve Gollery
> Sent: Tuesday, January 11, 2005 12:59 PM
> To: www-rdf-interest@w3.org
> Subject: classification inferences based on owl:disjointWith
> I'm using Jena with Racer as the DIG reasoner, using a test program
> based on the "Extended example" at
> http://jena.sourceforge.net/how-to/dig-reasoner.html.
> 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/Organization"/>
>      <owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Person"/>
>      <owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Project"/>
>    </rdfs:Class>
> 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
> rdfs:Class.
> Am I wrong about that?

No, I don't think so - that should be a valid inference (at least in owl
full). Maybe the foaf ontology doesn't fit the syntactic restrictions that
DLs require and so isn't imported properly (or at all)?

> Steven Gollery
> sgollery@cadrc.calpoly.edu


Geoff Chappell
Received on Wednesday, 12 January 2005 14:02:52 UTC

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