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Re: aboutEachPrefix? was Re: Namespaces wihtout "#" Was: Few CWM Bugs

From: Jonathan Borden <jborden@mediaone.net>
Date: Fri, 4 Jan 2002 19:45:16 -0500
Message-ID: <018701c19582$3f5c1150$0a2e249b@nemc.org>
To: "Mark Nottingham" <mnot@mnot.net>
Cc: "Tim Berners-Lee" <timbl@w3.org>, <www-rdf-interest@w3.org>
Mark Nottingham wrote:

>...how would a Web server know
> that the URI http://www.example.com/images/foo.gif should be mapped
> to the file at /www/example/htdocs/images/foo.gif. Similarly, the Web
> server needs a mechanism to decide what Content-Type to send with the
> representation; an efficient way to do this is to look up the
> filename extension in a local map. In both cases, the namespace is
> fully under the control of the authority; they're using the structure
> they've defined as a convenience.

Err, that would be part of the "dereferencing" process and obviously is
allowed under Tim's axiom.

>
> Allowing RDF to peek inside URIs will allow publishers to makes
> statements about their URIs without enumerating each and every
> resource that they publish (difficult, if not impossible, considering
> things like queries). ...


That reminds me of the old NASA story about the engineer who derived a
formula that yielded negative velocities, so he simply added a convenient
"-1" factor and well the rest is history, as was that engineer's career when
found out ...

The point is that if we are creating a logical system, if we are publishing
axioms that are identified by URIs, then we cannot ignore such principles
merely for convenience.

I am not opposed, in principle, or prima facie, to defining properties of
URIs based upon some method of parsing the URI as a string, certainly that
is how URL dereferencing works, and so we are familiar with this process.
The problem is that I have also read and listened to the arguments _for_
keeping URIs opaque, and so unless the axioms governing or describing the
intended behavior of the "RDF system" are written down and taken as a whole,
I have a great deal of trouble understanding the greater implications for
the system.

My particular worry is that it would make the general implementation of
inferencing systems quite difficult, but that is just my hunch.

Jonathan
Received on Friday, 4 January 2002 19:46:30 GMT

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