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RE: Meaning of normative references [was: Update on namespaces]

From: Andrew Layman <andrewl@microsoft.com>
Date: Tue, 15 Jul 1997 21:10:22 -0700
Message-ID: <7BB61B44F197D011892800805FD4F79201115B7A@RED-03-MSG.dns.microsoft.com>
To: Sam Hunting <sgmlsh@CAM.ORG>
Cc: w3c-sgml-wg@w3.org, lee@sq.com
Unless you mean this as some sort of reference to Positivist philosophy,
I think the meaning is clear: XML is a subset of SGML. If something is
valid XML, then it is valid SGML.  This has nothing to do with how such
validity is tested, it is a simple statement of fact regarding the two
notational systems and the relation between documents conforming to the
rules of each.

> -----Original Message-----
> From:	Sam Hunting [SMTP:sgmlsh@CAM.ORG]
> Sent:	Tuesday, June 24, 1997 7:57 PM
> To:	lee@sq.com
> Cc:	w3c-sgml-wg@w3.org
> Subject:	Re: Meaning of normative references [was: Update on
> namespaces]
> [Taken as read: fulsome commendation to *both* Len and Dan for
> effective
> use of rhetoric.]
> > Instead, we should have a note that says that every valid XML
> document
> > will ipso facto conform to ISO 8879, and possibly refer the
> interested
>        ^^^^^^^^^^
> > reader to that document.
> Meaning: "By that very fact" (as opposed to ipso jure "by the
> operation of
> the law itself", says the OED.)
> But how is this "fact" to be tested? (It's like saying "every bottle
> of
> beer ipso facto contains 4% alchohol", when there's no way of actually
> testing specific gravity for a reality check on any given bottle.) 
> Ipso facto validity will come down, in practice, to validation by the
> parser at hand. ("Feels like 4% to me!") 
> > cannot be a normative requirement for XML conformance.  Rather, the
> > XML spec must stand alone, but the resulting valid XML documents
> must
> ^^^^
> > always be valid SGML documents.  So any reference to SGML in the XML
> > spec must be for interest, not one that forces people to read ISO
> 8879:1986.
> Again, how "must" (and why not "shall"?)
> Would it be possible to move to "ipso jure" xml validity by
> introducing
> the concept that SGML is "operationally normative" with respect to
> XML?
> By "operationally normative" I mean: a free and technically excellent
> parser (say, nsgmls)  is set up at a sensible site (say ...). The
> location
> of the parser and the command line to supply it are published in the
> specification. Then, if someone (say, a contractor who is obligated to
> produce SGML-valid XML, or the grad student at the end of his/her
> one-week
> trek) can feed that parser the XML in question, and if there are no
> errors, the XML is SGML.
> Returning to the beer metaphor, under this proposal the person with
> the
> bottle in hand doesn't have to read a physics textbook to test that
> the
> beer is 4%. 
> S.
> P.S. Incidentally, Len is correct that if the XML specification does
> what
> it says it does (that is, if the words "Valid XML documents are SGML
> documents in the sense described in 8879" are true in reality as well
> as
> intent), no one will ever have to read actually read the SGML
> standard,
> because no need for clarification will ever arise, and the XML
> specification will be able to stand alone. 
> But that is asking humans (the ERB, us) to create a perfect
> specification
> -- not possible in this world, no matter how well anyone "does their
> job." 
> Therefore, some method of allowing SGML to be normative ipso facto and
> ipso jure is necessary that does not require the standard to be read
> is
> needed: why I propose the concept of "operationally normative."
Received on Wednesday, 16 July 1997 00:10:25 UTC

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