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

From: Michael Mealling <michael@neonym.net>
Date: 10 Jul 2003 11:56:28 -0400
To: Patrick.Stickler@nokia.com
Cc: sandro@w3.org, hardie@qualcomm.com, uri@w3.org
Message-Id: <1057852588.27314.163.camel@blackdell.neonym.net>

On Thu, 2003-07-10 at 11:14, Patrick.Stickler@nokia.com wrote:
> > Its all about _layers_ Patrick. 
> 
> No shit. Don't patronize me.

Sorry 'bout that. I'm just seeing layer violations in just about
everything you're suggesting.....

> You explicitly stated that two lexically distinct URIs denote
> *different* resources. 

Given the lack of language in 2396 about comparing resources I can't see
how you can suggest otherwise.

> That's simply wrong. And means that the lower layer is
> constraining higher layers against co-denotation.

No. I'm simply saying that higher layers have to create new definitions
for 'resources' that are a superset of the one used by 2396. I.e. there
are URI-Resources and there are SW-resources (or LDAP-resources, or
Gopher-resources). A SW-resource can be referred to as a URI-Resource
but if that is done by something that isn't SW aware then it must not be
expected to 'know' about SW concepts of equivalence.

> It is true that RFC 2396 is unnable to say anything about equivalence
> of denotation. Fine. But it should also clearly reflect that
> there is no restriction against co-denotation of URIs.

Correct. There is no restriction of co-denotation because 2396 is
completely silent on subjects like that. That is for applications and
systems to determine. Its just the same thing with IP addresses. RFC 791
specifies no methods for saying that two different IP addresses denote
the same host. That is something that's left for things like /etc/hosts
files and DNS. RFC 2396 is the same way, it makes no statements about
co-denotation since that is something that is left to things like RDF
and OWL. URIs won't solve that problem for them, but it doesn't get in
their way of solving it either.

> > ...
> > > But you seem to be asserting that co-denotation is prohibited,
> > > not simply possible. There is nothing left for OWL or other
> > > layers to contribute, without coming into direct conflict with
> > > what you appear to be asserting, that lexically distinct URIs
> > > always denote distinct resources.
> > 
> > Its prohibited _at that layer_ by the simple fact that you have no
> > language in which to express any of those concepts. 
> 
> Sorry. No. Just because you don't have the language to express
> something does not mean it is either impossible or prohibited.

Its impossible at that layer. Do it at a higher one.

> It simply means you can't tell.
> 
> It's about granularity. RFC 2396 does not provide sufficient
> granularity of specification to clarify co-denotation of 
> resources. But that doesn't mean it is prohibited.

Correct.....

> That's like saying that atomic structures are prohibited because
> at the "layer" of my eyes, I can't see them.

I didn't get that last analogy but the statement its based on is
correct. co-denotation is something that RDF does to RDF-resources, not
URI-resources.....

-MM
Received on Thursday, 10 July 2003 12:36:36 UTC

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