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Re: Issues danc-01 Re: 2 formalities in RDF concepts

From: Jan Grant <Jan.Grant@bristol.ac.uk>
Date: Wed, 29 Jan 2003 09:41:07 +0000 (GMT)
To: Dan Connolly <connolly@w3.org>
cc: Jeremy Carroll <jjc@hpl.hp.com>, RDFCore Working Group <w3c-rdfcore-wg@w3.org>
Message-ID: <Pine.GSO.4.44.0301290938410.11576-100000@mail.ilrt.bris.ac.uk>

On Tue, 28 Jan 2003, Dan Connolly wrote:

> > Jeremy's talking about *syntactic* equality (ie, "X equals Y" means
> > "every expression involving X can be rewritten with Y substituted for it
> > and the expression's value is preserved"),
>
> Hmm... I wasn't familiar with that idea before... I'll have
> to think it over.
>
> But my intuition says the difference between syntactic
> equality and identity matters to the RDF spec.
>
> For example, if X and Y are distinct graphs that
> art syntactically equal, what's the cardinality
> of the set {X, Y}? It's 2, right?
>
> The model theory spec does stuff like putting
> graphs into sets, and I think it matters what
> the cardinality of the resulting set is;
> if X and Y are the graphs arising from
> the n-triples document jeremy gave as
> an example, I think the model theory
> spec depends on the cardinality of {X, Y} being 1.
>
> But I'm not certain. It could be that it doesn't
> matter.

It doesn't; it's akin to thinking about how many number 10s there are:
you can take a view, but it's irrelevant to the way you do arithmetic.

-- 
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/
The Java disclaimer: values of 'anywhere' may vary between regions.
Received on Wednesday, 29 January 2003 04:42:08 EST

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