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RE: DAML+OIL: Questions & Improvements.

From: Ian Horrocks <horrocks@cs.man.ac.uk>
Date: Tue, 30 Jan 2001 10:24:29 +0000 (GMT)
Message-ID: <14966.38493.815924.679129@excalibur.cs.man.ac.uk>
To: Dan Brickley <danbri@w3.org>
Cc: "King . Dany" <DKing@drc.com>, "'www-rdf-logic'" <www-rdf-logic@w3.org>
On January 29, Dan Brickley writes:
> 
> On Mon, 29 Jan 2001, Ian Horrocks wrote:
> 
> > > Syntactically however, it is... mostly (discrepancies: 1. RDF is requires
> > > acyclic subclass relations, DAML+OIL allows cyclic subclass relations; 2.
> > > DAML+OIL requires one syntax for cardinality to avoid exposed content, thus
> > > other equivalent and legal RDF syntaxes are illegal for DAML+OIL
> > > cardinality; 3. RDF allows only one range restriction per property, DAML+OIL
> > > allows multiple; 4. the "daml:collection" doesn't exist in RDF).
> >
> > 1 and 3 are likely to change in RDFS.
> 
> Ahem! Pointer please to evidence for claim (1). Or a PaperTrail
> (http://www.w3.org/DesignIssues/PaperTrail).
> 
> Regarding (3), my inclination is to agree (and also fix rdfs:domain). The
> important thing with domain/range is to define what they mean, not how
> many times one can write down statements using them. The RDFS prose gets
> this wrong imho.

There have been extensive discussions about (3) on the RDF list(s),
w.r.t. both range and domain, most/all of which led to the conclusion
that the original specification was a mistake and should be
changed. My claim regarding (1) is rather more doubtful. The evidence
is as follows:

a) I spoke to Ora Lassila about it and he didn't raise any strong
objections.

b) The restriction is clearly senseless, so it is bound to be dropped
eventually.

Regards, Ian
Received on Tuesday, 30 January 2001 06:00:55 GMT

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