# Re: Wish for MathML 3: version attribute

From: David Carlisle <davidc@nag.co.uk>
Date: Mon, 17 Sep 2007 09:52:33 +0100
Message-Id: <200709170852.l8H8qXjC031724@edinburgh.nag.co.uk>



> b) I really like the idea of a different namespace: MathML is mostly
> embedded in other documents, and namespaces are the way to identify
> it. A new namespace would mean that existing software will not
> immediately recognize MathML 3, but it will be easily adaptable.

Speaking personally I'm strongly opposed to a new namespace. If you
change the namespace of a language you change the name of __every__
construct in the language, so it's not really a new version, but rather
a completely different language.

Currently you can write a mMthML to TeX translator (say) that goes
<xsl:template match="m:frac">\frac{.....
and this same code will work for mathml 1 2 and 3.If MathML 3 were in a
different namespace it would no longer work for MathML3, and if the
namespoace binding in the styleshete were changed to a new mathml3
namespace, it would no longer work for MathML2 or 1. It would be very
difficult to make the code work for all versions of MathML.

A version attribute (that's optional, with a recommendation that it not
be used unless mathml3 features are used) is far less intrusive. It can
be just taken as a hint, at the start of the instance that some new
features are being used.

Modifying the MIME headers is workable in cases where mime types are
relevant, but as others have said this is probably the minority of cases
for MathML as in practice it is usually embedded in a larger document
and the MIME type system isn't really expressive enough to separately
version each component of a mixed namespace document.

David

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