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Re: TEST, SEM: test cases for dark triples

From: <jos.deroo.jd@belgium.agfa.com>
Date: Sat, 27 Apr 2002 22:08:05 +0200
To: pfps@research.bell-labs.com
Cc: jos.deroo.jd@belgium.agfa.com, jjc@hplb.hpl.hp.com, www-webont-wg@w3.org
Message-Id: <OFA765F27B.EFD18E77-ONC1256BA8.006937A1@bayer-ag.com>

> [...]
>
> > That worked as such but was meaningless/misleading and is now thrown away.
> > We now have (as a matter of test) another possible pair of er
> >
> > { ?s ?p ?o . ?s a [ owl:restrictionOf ( ?p ?C ) ] } log:implies { ?o a ?C }
.
> >
> > { ?s ?p ?o . ?o a ?C } log:implies { ?s a [ owl:restrictionOf ( ?p ?C ) ] }
.
>
> Well these are a rather strange pair of inference rules.  They certainly
> are not correct for any of the DAML+OIL constructs, nor for any OWL
> construct that I have seen proposed.
>
> Could you please give me an informal description of what owl:restrictionOf
> is supposed to mean?

the ?x is shorthand "for all x elements of the domain of discourse"
?s ?p ?o . ?s a [ owl:restrictionOf ( ?p ?C ) ] in the premise is
actually ?s ?p ?o . ?s a ?x . ?x owl:restrictionOf ( ?p ?C )
(btw the . is shorthand for logical conjunction)

owl:restrictionOf is a rdf:Property whose
rdfs:domain is owl:Class and whose rdfs:range is owl:Seq
i.e. a sequence of a rdfs:Property followed by an owl:Class
also owl:restrictionOf is an owl:UnambiguousProperty
so we don't need a Skolem function in the second consequent

an example could be something like
 :Person rdfs:subClassOf [ owl:restrictedBy ( :hasParent :Person ) ] .
which is btw also an example of :Person circularity

--
Jos
Received on Saturday, 27 April 2002 16:10:31 GMT

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