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Re: Two questions about bagid

From: Jan Grant <Jan.Grant@bristol.ac.uk>
Date: Tue, 11 Feb 2003 22:46:22 +0000 (GMT)
To: Tim Berners-Lee <timbl@w3.org>
cc: RDF Core <w3c-rdfcore-wg@w3.org>, www-rdf-comments <www-rdf-comments@w3.org>
Message-ID: <Pine.GSO.4.44.0302112242000.8655-100000@mail.ilrt.bris.ac.uk>

On Tue, 11 Feb 2003, Tim Berners-Lee wrote:

> Another question is about the semantics.
> I understand that an id  :i  on the statement  { :superman :can :fly}
> should generate the statements
> :i a rdf:Statement;  rdf:subject :superman;   rdf:predicate :can;
> rdf:object :fly.
> :superman :can :fly.
> and I might want to use this to generate attribution:
> :lois :thinks :i.
> This would suggest that an owl reasoner (say) that knows that :superman
> and
> :clarkekent are daml:equivalent should be able to infer that
> :i a rdf:Statement;  rdf:subject : clarkekent;   rdf:predicate :can;
> rdf:object :fly.
> : clarkekent :can :fly.
> :lois :thinks :i.
> This seems counterintuitive, as one would expect it allow one to
> conclude
> that the modified statement is due to the original source.
> Some form of quoting around the subject, predicate
> and object would seem necessary.
> I have been guilty of ignoring this rather complicated bit of the spec,
> and wonder whether others have done the same.
> A developer.

I've had this conversation with Danbri before. The owl reasoner you
posit has superman and clarkkent denoting the same thing (ie, it applies
an interpretation that a comic reader would agree with). Strictly
speaking, from the comic reader's point of view (ie, in that
interpretation) the conclusion is correct: Lois thinks that the person
denoted by "Clark Kent" can fly, which he can, 'cause he's super.

Lois wouldn't reason using the same interpretation, so her conclusions
would be different.

jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/
Tel +44(0)117 9287088 Fax +44 (0)117 9287112 http://ioctl.org/jan/
I am now available for general use under a modified BSD licence.
Received on Tuesday, 11 February 2003 17:49:23 UTC

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