- 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
> [...]
>
> > 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 UTC