W3C home > Mailing lists > Public > www-math@w3.org > September 2008

Re: content markup newbie questions

From: David Carlisle <davidc@nag.co.uk>
Date: Wed, 17 Sep 2008 21:51:31 +0100
Message-Id: <200809172051.m8HKpVVQ010407@edinburgh.nag.co.uk>
To: prushfor@NRCan.gc.ca
Cc: www-math@w3.org

Unfortunately in a way, <declare> isn't widely supported by rendering
agents, certainly the ctop.xsl stylesheet that you mentioned just
discards it. This is conformant but perhaps less helpful than you may want.

As far as presentation goes <declare> even if fully implemented just
gives a hint that the declared symbols, when they occur later in the
expresssion, should be rendered differently. The declare expression
itself isn't expected to be rendered.

Thus the default rendering of your math expression, which only consists
of declare is empty.

The main problem with declare is that a useful declaration maechanism
needs to have (at least) document scope but mathml itself can only 
define a single math element. If defining a compound document format
that uses mathml for math fragments in a larger document context it is of
course possible to define things with a wider scope (see for example
omdoc as an example) and hopefully one day we'll get  defined profile of
xhtml+mathml with that kind of functionality built in.

However today, For use in a web browser, I'd mark up the definitions
that you posted as equations rather than using declare.


The Numerical Algorithms Group Ltd is a company registered in England
and Wales with company number 1249803. The registered office is:
Wilkinson House, Jordan Hill Road, Oxford OX2 8DR, United Kingdom.

This e-mail has been scanned for all viruses by Star. The service is
powered by MessageLabs. 
Received on Wednesday, 17 September 2008 20:52:06 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:27:40 UTC