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Re: The range of the HTTP dereference function

From: Jonathan Borden <jonathan@openhealth.org>
Date: Wed, 27 Mar 2002 15:20:58 -0500
Message-ID: <056401c1d5cc$ea24a7c0$0a2e249b@nemc.org>
To: "Tim Berners-Lee" <timbl@w3.org>
Cc: <danc@w3.org>, "'www-tag'" <www-tag@w3.org>
Tim Berners-Lee wrote:
>
>
> No.   Look at your argument.
>
>  1. "Tim suggests one can deduce things from the fact that a URI
>   starts with http: and has no "#"."
>  2. "This would allow one to write this really ugly daml code."
>  3. "It would be awful if alll inference engines had to be use that code".
>
> I cry 'foul!"

Sure. I wrote this to make a point. You did suggest _some benefit_ for
inferencing engines if your position, which is certainly internally
consistent, were upheld. I question this: What tangible benefit would a real
inferencing engine gain from restricting the range of "http:" prefixed URIs?

>
> One important leson here is that *RDF users inhabit the same web
> as everyone else*.  RDF users's cannot use
> telnet://example.com/  to refer to a car, because there is a spec
> which says it is a telnet port.

Certainly RDF users inhabit the same web, however, the Roy, Mark et al.
argue that an "http" URI _can_ identify a car or a person. Your arguments
are certainly logical, and self consistent, but what _tangible benefit_ do I
get by believing you? What breaks unless I view things your way? What breaks
if I view things Roy's way?

>
> I could alternatively *try* to interpret the HTTP spec so that the
> URI identifies a car.  But then how would I represent, when
> the metadata came back about the thing, whether the creatorand
> expiry date were those of the car or something describing the car?

Right, so I need to keep the pointer and the thing pointed to straight. But
that is the difference between the resource and the resource representation,
no? I mean _you_ and _your home page_ can be given different URIs, no?

> HTTP could be extended to make that distinction, but it hasn't yet.
> And it is pretty powerful in implementing a web of information
> objects. And with RDF, those information objects can describe,
> and give URIreferences to, anything at all.
> But it is wise to use a hash or you get an clash when you try to
> describe in RDFwhat you learned in HTTP.
>
> You ca't learn this from RDF alone.  You have to model HTTP in RDF
> and then you see the problem.

Well, I've done that for HTTP http://www.openhealth.org/xmtp/HTTP  and
earlier for SMTP http://www.openhealth.org/xmtp/ , and don't see a problem.

Jonathan
Received on Wednesday, 27 March 2002 15:24:06 GMT

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