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Re: Where DAML+OIL deviates from the RDF-Schema spec.

From: Jan Grant <Jan.Grant@bristol.ac.uk>
Date: Mon, 26 Feb 2001 10:53:41 +0000 (GMT)
To: Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>
cc: www-rdf-logic <www-rdf-logic@w3.org>
Message-ID: <Pine.GSO.4.31.0102261051340.29477-100000@mail.ilrt.bris.ac.uk>
On Sat, 24 Feb 2001, Frank van Harmelen wrote:

> [1]
> "Warning: The RDF Schema specification demands that the subclass-relation between classes
> must be acyclic. We believe this to be too restrictive, since a cycle of subclass
> relationships provides a useful way to assert equality between classes. Consequently,
> DAML+OIL places no such restriction on the subClassOf relationship between classes;"
>
> [2]
> "[in DAML+OIL] multiple domain expressions restrict the domain of P to the intersection of
> the class expressions.
> Warning: This is contrary to the semantics of the domain element in the RDF Schema
> specification, which we believe to be flawed."
>
> [3]
> "Warning: Although the RDF Schema specification only allows one range restriction for each
> property, it seems quite natural to allow multiple range restrictions. These would then
> again be interpreted as saying that the range of P must be the intersection of all the
> class expressions."

These choices seem to be the right ones anyway.

-- 
jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/
Tel +44(0)117 9287163 Fax +44 (0)117 9287112 RFC822 jan.grant@bris.ac.uk
Axioms speak louder than words.
Received on Monday, 26 February 2001 05:55:27 GMT

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