[rdfweb-dev] namespace versioning

Danny Ayers danny666 at virgilio.it
Wed Jul 28 18:35:08 UTC 2004

Ian Davis wrote:

> if http://purl.org/vocab/relationship/friendOf is declared owl:sameAs

A couple of handwaves on this - owl:sameAs seems quite a tricky thing, 
especially in schemas/ontologies. For a start there's being sure of the 
identity, that neither end will change, see danbert's comment at [1] 
(I'm guessing this won't be a problem in this case). Also when applied 
to classes it breaks the material out of OWL DL by treating the classes 
as individuals. I'm fairly sure the effect as required (that instances 
of the classes etc will be treated the same) is available with 
owl:equivalentClass (or owl:equivalentProperty). What's more the same 
can be done using just RDFS inference -  A subClassOf B AND B subClassOf 
A gives you the same thing, though with clunkier notation. Even just 
subClassing/subPropertying in one direction may allow the inferences needed.

Although sameness seems to be a monster logicwise, as has been suggested 
hacking sameness-savvy into a parser should be pretty straightforward. 
My guess is it would be more useful to do it at the level of terms 
rather than namespaces. It should help versioning for a start - if some 
of the terms aren't equivalent, you can leave 'em out.


[1] http://lists.w3.org/Archives/Public/www-rdf-interest/2004Jun/0149.html



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