Re: RDF/XML shorthand for RDF reification

I'm not sure that I believe this.

I think that one consequence of using the shorthand would be that an
annotated axiom might not entail itself in OWL Full.

For example, how would one arrange it so that 

SubClass(Label("Foo") A B)

entails

SubClass(Label("Foo") A B)

in the OWL Full arena?

peter



From: Alan Ruttenberg <alanruttenberg@gmail.com>
Subject: Re: RDF/XML shorthand for RDF reification
Date: Tue, 1 Jul 2008 07:11:54 -0400

> On Jun 26, 2008, at 7:16 AM, Peter F. Patel-Schneider wrote:
> 
> > 2/ Changing to named nodes would change the OWL Full semantics.  A
> >    careful check would have to be made to see whether any interesting or
> >    useful inferences could change.
> 
> 
> According to Michael this is one not a problem. I'm still thinking about issue 1/.
> 
> He says:
> 
> > Short answer: There are no additional consequences for OWL Full.
> >
> > Longer answer: Just have a look at the OWL Full Wiki:
> >
> >   <http://www.w3.org/2007/OWL/wiki/
> > FullSemanticsAxiomAnnotations#Semantics>
> >
> > The "Main semantic condition" there is applicable to both cases, with a bNode
> > or with an URI at the LHS. That's not because I wanted to make this semantic
> > condition more general as in OWL DL - I promise that I always try hard to be
> > as close to the DL semantics as possible. The point is that in an RDF
> > compatible semantics, it is not possible to restrict axioms to such RDF graphs
> > which only have a bNode as their LHS. This would be a syntactic restriction,
> > which is not possible in OWL Full - which is a major distinction between OWL
> > Full and OWL DL.
> >
> > So this whole current discussion about named axioms is really only an OWL DL
> > topic. It's the question whether to extend the reverse RDF mapping to cases,
> > where the LHS of an axiom annotation may be an URI, or not. OWL Full is
> > completely indifferent about this question. In particular, in my current
> > proposal, you will always receive the axiom triple as a result, whether the
> > LHS node is a bNode or a URI.

Received on Tuesday, 1 July 2008 11:29:22 UTC