- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Tue, 16 Mar 2004 11:51:54 +0100
- To: "Andrew Newman" <andrew@tucanatech.com>, "RDF Interest" <www-rdf-interest@w3.org>
> Geoff Chappell wrote:
> > How could it be wrong?
> >
> > If you have two statements:
> >
> > :_a <b> <c>
> > :_b <b> <c>
> >
> > You have no way of knowing if _a and _b are the same as or different
> > from each other, nor can you ever know (since a bnode has no globally
> > usable name, you can never learn more facts about either).
> >
>
> I agree - at least without OWL. I thought what Adam wanted was someway
> to remove either :_a or :_b.
Following the RDF semantics and any legal extensions the meaning of the
graph
> > :_a <b> <c>
> > :_b <b> <c>
is identical to
> > :_b <b> <c>
hence it is a sensible, useful and conformant operation to throw one of the
triples away. (At least in some applications).
In other application, such as an RDF editor, this would be less than useful.
>
> With the merge example I thought you were doing just that. So it's not
> okay to merge:
>
> {[http://www.w3.org/2000/01/rdf-schema#label] #(new Resource())
> "Intellidimension Inc."}
>
> with:
>
> {[http://www.w3.org/2000/01/rdf-schema#label]
> [http://www.intellidimension.com] "Intellidimension Inc."}
>
> They're [predicate, subject, object], right? You should get both
> statements in the merged model.
>
In a syntactic merge yes - but if you wish to then simplify the result using
RDF Semantics you can discard the first triple: it is merely a
generalization of the second. Discarding it would only be invalid in an
application which does not conform to RDF Semantics.
An OWL Full application does conform to RDF Semantics.
Jeremy
Received on Tuesday, 16 March 2004 05:52:51 UTC