RE: Proposal: new top level domain '.urn' alleviates all need for urn: URIs

But this says nothing whatsoever about equivalence
of denotation, only about lexical equivalence of the
URIs themselves.

While it is true that applications operating in terms
of RFC 2396 alone might presume that two lexically
distinct URIs denote different resources (entities),
that does *not* mean that any two URIs *can't* or
*don't* denote the same resource.

The purpose of the Semantic Web, and tools such as
OWL, is precisely to provide a standardized means of
providing such information to such applications.

Surely RFC 2396 is not intended to prohibit the
co-denotation of URIs?

Patrick

--
Patrick Stickler
Nokia, Finland
patrick.stickler@nokia.com
 
> -----Original Message-----
> From: ext Michael Mealling [mailto:michael@neonym.net]
> Sent: 09 July, 2003 20:27
> To: Tim Bray
> Cc: Sandro Hawke; Stickler Patrick (NMP/Tampere); hardie@qualcomm.com;
> uri@w3.org
> Subject: Re: Proposal: new top level domain '.urn' alleviates all need
> for urn: URIs
> 
> 
> 
> On Wed, 2003-07-09 at 12:58, Tim Bray wrote:
> > Michael Mealling wrote:
> > 
> > 
> > > I don't know. You're using a definition of equality drawn 
> from OWL and
> > > not from RFC 2396. I don't use OWL and thus never intended for its
> > > definition of 'equality' to be used in any comments I 
> made. When I talk
> > > about URIs _universally_ I make it a point to use only 
> terms that are
> > > universal for all possible applications, past, present 
> and future. That
> > > means the only definition of equality that's available to 
> me is the one
> > > found in RFC 2396.
> > 
> > Note that the RFC2396bis redraft-in-progress has, in its 
> section 6, a 
> > rather more nuanced and thorough discussion of the notion of 
> > "equivalence" of URIs and resources.  (Disclosure: I wrote 
> the first 
> > draft of the section).
> > 
> > http://www.apache.org/~fielding/uri/rev-2002/rfc2396bis.html
> 
> Yes. And even there it says this which is much more correct:
> 
> 
> "For this reason, determination of equivalence or difference 
> of URIs is
> based on string comparison, perhaps augmented by reference to 
> additional
> rules provided by URI scheme definitions. We use the terms "different"
> and "equivalent" to describe the possible outcomes of such 
> comparisons,
> but there are many application-dependent versions of equivalence."
> 
> 
> plus this:
> 
> And in 6.2.4 Protocol-based Normalization:
> 
> "Obviously, this kind of technique is only appropriate in special
> situations."
> 
> All of which re-iterate that application-dependent 'sameness' 
> of the end
> set of bits, actions, etc is not something you can make 
> statements about
> for the generalized URI universe. BTW, I would suggest that you change
> that last sentence in 6.2.4 to "Obviously, this kind of technique is
> only appropriate in special situations and is not universally 
> applicable
> across URI schemes or protocols".
> 
> I remember the discussion at the BOF on this document and one of the
> suggestions was to create another name for items that we humans call
> resource but which don't yet have URIs bound do them or which we would
> like to talk about outside the URI-constrained universe. We 
> never agreed
> on such a word but I still think it has utility in fixing this
> discussion about URIs, Resources and 'sameness'....
> 
> -MM
> 
>

Received on Thursday, 10 July 2003 09:20:31 UTC