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Re: range, domain: Conjunctive AND disjunctive semantics both supportable

From: Ian Horrocks <horrocks@cs.man.ac.uk>
Date: Mon, 2 Oct 2000 17:37:34 +0100 (BST)
To: Graham Klyne <GK@dial.pipex.com>
Cc: rdf interest <www-rdf-interest@w3.org>
Message-ID: <14808.47348.739109.641052@localhost.localdomain>
On October 2, Graham Klyne writes:
> Ian,
> 
> I think what you describe has exactly the same effect as Jan Grant's recent 
> suggestion:
> 
> >and loosely:
> >
> >P has a range of (a member of the union of A and B)
> >
> >         A --[rdfs:subclassOf]-> anon:C
> >         B --[rdfs:subclassOf]-> anon:C
> >         P --[rdfs:range]-> anon:C
> >
> >(give anon:C a real URI if you prefer).
> 
> except that Jan's approach doesn't depend on additional 
> application-specific awareness.  Or am I missing something?

You are missing something (in fact 2 things).

1) Jan's approach doesn't express the fact that the range restriction
is EXACTLY (A or B) but that it is some class that subsumes (A or
B).

2) Jan's approach leads to the introduction of (a possibly large
number of) anonymous classes that unnecessarily clutter up the class
hierarchy.

Regards, Ian
Received on Monday, 2 October 2000 15:38:18 GMT

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