W3C home > Mailing lists > Public > www-webont-wg@w3.org > March 2002

Re: more on a same-syntax extension from RDF(S) to OWL

From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
Date: Tue, 5 Mar 2002 00:05:17 +0100
To: pfps@research.bell-labs.com
Cc: "www-webont-wg" <www-webont-wg@w3.org>
Message-ID: <OF0DD0A5F7.1DDA16E0-ON41256B72.00782AA5@agfa.be>

> > [...]
> >
> > > So, to be more precise it should have been
> > >
> > >
> > > log:entails
> > >   _:1 owl:oneOf ( _:2 ) .
> > >   _:2 a owl:Restriction .
> > >   _:2 owl:onProperty rdf:type .
> > >   _:2 hasClassQ _:1 .
> >         ^owl:
> > >   _:2 maxCardinalityQ "0" .
> >         ^owl:
> >
> > OK Peter, I've re-re-re-ad your mail and think
> > I understand it better now
> > BUT please try to help us with the following:
>
> > 1. using such entailment rules as in
> >    http://www.agfa.com/w3c/euler/owl-rules.n3
> >    (this is just further play/elaboration of the
> >    RDFS MT entailment rules as in
> >    http://www.agfa.com/w3c/euler/rdfs-rules.n3)
> >    we can never derive a ... owl:oneOf ... statement
> >    (there is just no fact, nor rule consequence
> >    that matches it, so in fact we already fail there)
> >    so how could it ever be satisfied???
>
> I'm not sure why you are asking the question, but nevertheless ...

thanks

> I agree that http://www.agfa.com/w3c/euler/owl-rules.n3 does not sanction
> any oneOf consequences.  Therefore, you will not get
>    John a person .
> to imply
>         John a [ owl:oneOf ( John ) ].
> from http://www.agfa.com/w3c/euler/owl-rules.n3.
>
> All this says, however, is that there are desirable inferences that
> http://www.agfa.com/w3c/euler/owl-rules.n3 does not sanction, i.e.,
> http://www.agfa.com/w3c/euler/owl-rules.n3 is incomplete.

good point, I've added
  { ?L owl:item ?x } log:implies { ?x a [ owl:oneOf ?L ] } .
so now
  the-empty-graph
log:entails
  :John a [ owl:oneOf ( :Frans :John :Mary ) ] .
but that still doesn't give us an empty hypothesis to entail
  _:1 owl:oneOf ( _:2 ) .
I will think further...

> Are you claiming
> that it is complete?

No, and there's no plan to become complete ;-)

> > 2. if that can indeed be entailed,
> >    could you please SHOW THE PROOF???
>
> Proof in what system?

OK, I was just trying to get *some* evidence

> I have indicated that this would be a semantic
> consequence in a model theoretic semantics that supports inferences that
I
> claim are desirable.

fair enough, I just haven't seen/understood it

> I have not written down a proof theory that is
> sound and complete for this model theory.
>
> > --
> > Jos De Roo
>
> peter

--
Jos
Received on Monday, 4 March 2002 18:05:54 GMT

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