Re: RDF/XML shorthand for RDF reification

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.