Re: Error in owl2-rdf-based-semantics document - superclass of owl:ObjectProperty

Hello Barry!

The inclusion of the triple in Table 6.5 is intended and is not an error.

Under the OWL 2 RDF-Based Semantics, owl:ObjectProperty does not only 
denote a sub class of rdf:Property, but the two classes are meant to be 
equivalent. You can see this informally stated in Figure 1 in Chapter 1, 
and it is normatively specified in Table 5.2 in Chapter 5, according to 
which

     ICEXT(I(owl:ObjectProperty)) = IP = ICEXT(I(rdf:Property))

Hence, it is true that the following two axiomatic triples are valid 
under the OWL 2 RDF-Based Semantics:

     (1) owl:ObjectProperty rdfs:subClassOf rdf:Property .

and

     (2) rdf:Property rdfs:subClassOf owl:ObjectProperty .

In fact, you can find triple (1) in Table 6.1 "Axiomatic Triples for the 
Classes of the OWL 2 RDF-Based Vocabulary", so the triple is really 
included in the given set of axiomatic triples.

Table 6.5 contains, as its name suggests, some additional axiomatic 
triples that are true under the OWL 2 RDF-Based Semantics, but have not 
been mentioned in any other table (for certain design decisions not 
mentioned here). As triple (2) is valid under the OWL 2 RDF-Based 
Semantics, it has been decided to include the triple in that table. You 
can also find there analogue triples fo the relationships between, for 
instance, rdfs:Class and owl:Class, and between rdfs:Resource and owl:Thing.

Best Regards,
Michael Schneider

Am 29.05.2013 15:30, schrieb Barry Bishop:
> Dear working group,
>
> I believe there is an error in:
>
>      http://www.w3.org/TR/owl2-rdf-based-semantics/
>
> In "Table 6.5: Additional Axiomatic Triples for Classes and Properties
> of the RDFS Vocabulary" there is the axiomatic statement:
>
>      rdf:Property rdfs:subClassOf owl:ObjectProperty .
>
> I believe it should be the other way round:
>
>      owl:ObjectProperty rdfs:subClassOf rdf:Property .
>
> This would make more sense to me and be consistent with:
>
>      http://www.w3.org/TR/owl-ref/#Property
>
> where it states:
>
>      "Both owl:ObjectProperty and owl:DatatypeProperty are subclasses of
> the RDF class rdf:Property"
>
> Please advise,
> barry
>

Received on Wednesday, 29 May 2013 20:02:44 UTC