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

Re: mfenced as a special case of mrow -- Was: angle brackets in math

From: David Carlisle <davidc@nag.co.uk>
Date: Wed, 28 May 2008 19:47:58 +0100
Message-Id: <200805281847.m4SIlwLg013128@edinburgh.nag.co.uk>
To: hammond@csc.albany.edu
Cc: www-math@w3.org


Example 1.  An xml normalizer.  Surely that should not translate mfenced
            to mrow.  OK, so one says that an xml normalizer is not a
            mathml processor.  (But still I'm frowning.)


you mean in the sense of xml canonicalisation? Yes that doesn't see the
matml at all, so nothing in the mathml spec affects that, the document
may have <mathml:badname/. or an mfrac with three children or other
nonsensical constructs, they could still be normalised.


> in effect, mapped the mfenced to an mrow because it took the docs more
>  seriously  than I have been taking them.  

there is no semantic difference between an mfenced and its equivalent
mrow. The level to which a system can infer any semantics from
presentation mathml is an issue for that application not (directly) an
issue for mathml itself.

> Presentation markup is only minimally semantic, but I am concerned
> about conservation of semantics to the extent possible.

agreed.

> An mfenced represents the mathematical concept of list.  An mrow
> represents the concept of mathematical expression. 

disagree entirely. mfenced and mrow have the same implied semantics.
I'd typically use mfenced in marking up  x * (a + b)  in what sense 
(a + b) a "list" rather than a "mathematical expression".

> Why is it thought to be important to _define_ mfenced to be
> effectively an alias for profiled usage of mrow?

It's been in the language so long it predates me being in the working
group, so I can only report the way it is, not the discussions that went
in to that design:-)

David



________________________________________________________________________
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, 28 May 2008 18:48:35 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Saturday, 20 February 2010 06:13:01 GMT