W3C home > Mailing lists > Public > www-rdf-logic@w3.org > June 2001

Re: properties with classes as values?

From: David Martin <martin@ai.sri.com>
Date: Thu, 07 Jun 2001 10:05:46 -0700
Message-ID: <3B1FB46A.966B13BD@ai.sri.com>
To: "Sean B. Palmer" <sean@mysterylights.com>
CC: www-rdf-logic@w3.org
Sean -

Thanks much for your effort on this example, but it seems to me there
are still some things to be clarified, and further (as you yourself
point out) you haven't shown how to express what I want.

"Sean B. Palmer" wrote:
> > What I want is that the value of myProperty can be
> > *any* class.
> Then the range of it is rdfs:Class.
>    :myProperty rdfs:range rdfs:Class .

First (minor point) - any reason why I can't use daml:Class as my range?

> > >    :x rdfs:range
> > >       [ daml:intersectionOf
> > >           (:Class [ rdfs:subClassOf :Animal ]) ] .
> > > XML RDF of these things available upon request...
> >
> > I would very much appreciate seeing the last sample above
> > in DAML+OIL.
> <daml:Class rdf:ID="x">
>  <rdfs:range>
>   <rdf:Description>
>    <daml:intersectionOf parseType="daml:collection">
>      <daml:Class rdf:ID="Class"/>
>      <rdf:Description>
>        <rdfs:subClassOf rdf:resource="#Animal"/>
>      </rdf:Description>
>    </daml:intersectionOf>
>   </rdf:Description>
>  </rdfs:range>
> </daml:Class>
> In prose: the range of class "x" is an intersectionOf "#Class" and
> something which is the subClassOf "#Animal"; which most likely isn't
> what you really want to say.

First, can a Class have a range?  Or did you mean to declare property x,
rather than class x?  That would be a better start towards what I want,
which is to declare the range of a property (called myProperty) to be
the set of subclasses of #Animal.  

Second, you're right - what you've written above is NOT what I really
want to say; that is, I do NOT want to say this:

   the range of myProperty is the intersectionOf "#Class" and some class
which is a subClassOf "#Animal"

So I think my challenge is still open - that is, to declare that:

   the range of myProperty is the set of subclasses of #Animal.

> ...


- David
Received on Thursday, 7 June 2001 13:08:39 UTC

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