Re: RDF/XML shorthand for RDF reification

I'm not an expert in OWL Full matters, but I guess that Peter is  
concerned that the root node of the reified axiom will now become a  
named node, that there could/would be different names in different  
ontologies, and that the entailment would thus be broken.


On 1 Jul 2008, at 13:19, Michael Schneider wrote:

> Hi Peter!
> Peter F. Patel-Schneider wrote:
>> 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?
> I am not certain that I correctly understand the question. In  
> general (by
> Simple Semantics) every RDF graph entails itself. So as long as a  
> DL axiom
> has a mapping to RDF, the respective RDF graph entails itself in  
> OWL Full.
> In the case of your example axiom above, the RDF mapping would be  
> (but using
> a URI instead of a bNode for the axiom):
>   ex:axiom rdf:type owl:Axiom
>   ex:axiom rdf:subject A
>   ex:axiom rdf:property rdfs:subClassOf
>   ex:axiom rdf:object B
>   ex:axiom rdfs:label "Foo"^^xsd:string
> The RDF/XML serialization would be pretty compact in this case, but  
> this is
> has no impact on OWL Full, which only deals with the (abstract) RDF  
> graph.
>> peter
> Cheers,
> Michael
>> From: Alan Ruttenberg <>
>> 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:
>>>>   <
>>>> 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 18:22:19 UTC