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Re: Why isn't FunctionalProperty a subClassOf owl:ObjectProperty?

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 06 Mar 2003 08:32:23 -0500 (EST)
Message-Id: <20030306.083223.34991779.pfps@research.bell-labs.com>
To: macgregor@ISI.EDU
Cc: www-rdf-logic@w3.org

From: Bob MacGregor <macgregor@ISI.EDU>
Subject: Re: Why isn't FunctionalProperty a subClassOf owl:ObjectProperty?
Date: Wed, 05 Mar 2003 16:36:29 -0800

> Peter,
> 
> At 09:06 AM 3/5/2003 -0500, Peter F. Patel-Schneider wrote:
> >From: Bob MacGregor <macgregor@ISI.EDU>
> >Subject: RE: Why isn't FunctionalProperty a subClassOf owl:ObjectProperty?
> >Date: Tue, 04 Mar 2003 15:18:55 -0800
> >
> > >
> > > GreaterThan is a transitive Datatype Property.
> > > Equals is a symmetric Datatype Property.
> >
> >Well, neither of these make much sense in OWL DL, domains and ranges of OWL
> >DL datatype properties are disjoint of necessity.
> >
> >They even don't have much utility in RDF, as you can't state any facts
> >about such properties, as literals can't be the subject of triples.
> >
> >peter
> 
> I hope you are wrong at some level.  This is really basic, and
> it OWL can't do it, then we really are in a sorry state.
> 
> I ought to be able to allocate a resource (a blank node) representing
> John's age, and another representing Fred's age, and then assert that
> John's age is greater than Fred's age:
> 
>       :age :John :_b1 .
>       :age :Fred :_b2 .
>       :_b1 :greaterThan :_b2 .

Hmm.  I forgot that blank nodes can denote literals, and that with the
recent changes to XML/RDF you can actually do interesting things with them.

> Are you claiming that
> 
>        :greaterThan :domain :Integer.
>        :greaterThan :range :Integer.
> 
> are illegal triples?  If not, then why are my first three triples not
> allowable?

Well, the above triples are certainly acceptable.  However, that doesn't
make :greaterThan be the greater than relationship between integers.

It used to be the case that the first three triples could not be
communicated, which was the crux of my comments.  This is no longer the
case.

I still think that there is not much of interest that can be done here in
RDF, because RDF has no theory of data values, and no way to add such a
theory.
 
> Bob

peter
Received on Thursday, 6 March 2003 08:32:36 GMT

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