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Re: RDF Concepts and Data Model document

From: Tim Berners-Lee <timbl@w3.org>
Date: Fri, 20 Sep 2002 16:40:05 -0400
Message-ID: <00aa01c260e5$e6dcea10$84001d12@w3.org>
To: "Williams, Stuart" <skw@hplb.hpl.hp.com>, "Brian McBride" <bwm@hplb.hpl.hp.com>
Cc: <www-tag@w3.org>

1. Yes, indeed.  Maybe we should do it by namespace?


2. There is a related question which if it not an issue ought to be, when
mixing
languages -- whether to parse RDF which is inside non-RDF XML.

A.  to prohibit an RDF parser from taking such embedded RDF as being
asserted by the document, without further information,
N. Allow RDF parsers to "see through" any foreign XML as though it were
transparent, and parse what is inside. This makes it impossible to define
new XML tags to extend RDF into a more powerful language with any form of
quotation, or "or" or "not" for example.

Cwm, by the way, defaults to A will do B with the  cwm --rdf=T  flag.
A run-time flag is not a long term solution!

I think personally A is the only option to take, unless you give up
on using XML as the basis for future semantic web work such as RDFQ.
If we pursue (A), then the question is -- how can you let a  parser know
that
something like an RSS wrapper or HTML *is* supposed to be transparent?

- A notation in the document or in the schema?
- A notation about the namespace as a whole or an element?

How should the notation be done?

- A common XML schema element type which all transparent elements inherit
from?
- An RDF assertion somewhere (anywhere that is asserted in document or
schema!)

I think the RDF core group has to address the  mixing of  RDF  with other
languages. Every language spec should address namespace mixing.  We as a
community have been rather lax about it, partly from lack of experience of
how we want to do it.

Tim

PS: This is discussed in the 1999 article "Strawman unstriped syntax for the
semantic web" http://www.w3.org/DesignIssues/Syntax.html. specifically in
the note "RDF in HTML -transparent or not?"


----- Original Message -----
From: "Brian McBride" <bwm@hplb.hpl.hp.com>
To: "Tim Berners-Lee" <timbl@w3.org>; "Williams, Stuart"
<skw@hplb.hpl.hp.com>
Cc: <www-tag@w3.org>
Sent: Thursday, September 19, 2002 6:59 AM
Subject: Re: RDF Concepts and Data Model document


> At 03:51 18/09/2002 +0100, Tim Berners-Lee wrote:
>
> [...]
>
> >*       when used in an rdf document, someurl#frag means the thing that
> >is indicated, according to the rules of the application/rdf+xml mime
> >type as a "fragment" or "view" of the RDF document at someurl.
>
> As Martin Deurst has pointed out elsewhere, we also have to consider the
> situation when RDF containing someurl#frag is embedded in another
document,
> e.g. HTML or SVG.  The mime-type applicable to that document is not
> application/rdf+xml and thus RDF has no authority to define what it means.
>
> Brian
>
Received on Friday, 20 September 2002 16:40:08 GMT

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