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Re: #rdfms-difference-between-ID-and-about (every document is in the Web)

From: Dan Connolly <connolly@w3.org>
Date: Fri, 15 Jun 2001 14:00:44 -0500
Message-ID: <3B2A5B5C.C902A06A@w3.org>
To: Brian McBride <bwm@hplb.hpl.hp.com>
CC: Graham Klyne <Graham.Klyne@Baltimore.com>, rdf core <w3c-rdfcore-wg@w3.org>
Brian McBride wrote:
> 
> Dan Connolly wrote:
> 
> > You trust that I have a birthday even though you don't
> > know it, right? By the same token, it seems easy
> > enough to accept that resources have URIs even though
> > those URIs aren't always specified.
> 
> Forgive me butting in.  Is the set of real numbers
> a subset of the set of resources?  After all, they have identity.
> Note that URI's are countable and real numbers are not.

That's the subtlety I meant to set aside when I wrote:

| I think you've slightly overstated the case there,
| but the argument holds even the way you've phrased it, so...
 -- Fri, 15 Jun 2001 09:20:55 -0500

The way he phrased it, every resource has a URI-name.
The way I see it, any particular resource can be named
with a URI; that doesn't mean they all have (unambiguous) names,
as you point out: all real numbers are resources;
only denumerably many of them can be named with URIs.

Another subtlety that isn't relevant to the ID/about
issue is whether 'resource' is used in the general
sense of 'anything in the domain of discourse'
(i.e. things you can refer to using absolute-URIs-with-fragments)
or in the stricter sense of, roughly, 'something you can
get at via the network' (i.e. things you
can refer to using absolute-URIs-without-fragments).

I'd like for the revised RDF specs to use 'resource'
in the stricter sense, but in speaking of real
numbers as resources, of course we're using it
in the general sense.

The traditional logic-literature
term for the more general concept is 'object'; I'd
be happy to start using that in these WG discussions.

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Friday, 15 June 2001 15:00:54 EDT

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