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Re: MathML-Presentation questions

From: Michael Kohlhase <Michael_Kohlhase@asuka.mt.cs.cmu.edu>
Date: 26 Apr 2001 11:29:38 +0200
Message-Id: <200104241634.MAA30232@tux.w3.org>
To: Robert Miner <RobertM@dessci.com>
cc: habelg@micro-intel.com, www-math@w3.org
Dear Genevieve, dear Robert,

> > The company I work for uses MathML (and XML) for encoding educational 
> > contents. We also have the goal of translating our XML contents in many 
> > differents cultural domains. We have encountered some problems that we 
> > don't know how to resolve in MathML.

I think that you should also think about content/presentation tradeoff for
your application. Being able to translate into different cultural contexts
seems to call for a content-based solution here. 

Robert has mainly concentrated on presentation issues in his reply (the
unit stuff is more content-oriented). Bills reference to the OpenMath
content dictionaries gives some help here, even though they clearly have a
long way to go. Then the presentation MathML (and other formats like LaTeX)
could be generated by style sheets. 

Note that there is still the issue of coming up with the relevant defininig
documents for DefinitionUrl in <csymbol> (OpenMath CDs can serve as
that). And maintaining the relevant (language-specific) markup for it. I
have tried something like that in my OMDoc format (see
http://www.mathweb.org/omdoc) by keeping symbol-local presentation
information near the symbol definition. 

> > 5. mo: Invisible operators. Will you define an <mo>&InvisiblePlus;</mo> 
> > to markup a fraction like 1 1/2 (one and an half)?
> > If not, how do you propose to markup the implied plus in this
> > fraction?
> 
> You wouldn't ask it you knew the battle we've had over
> InvisibleTimes...  I think the only way to mark this up for
> presentation is a <mn> next to a <mfrac>.  Not very satisfactory, I
> realize.  

Again, in my mind the question about invisible operators is mainly an issue
of presentation/content markup, in this case trying to make presentation to
tricks that you really need content markup for. There you could write
something like
<apply>
  <csymbol DefinitionUrl="xxx">complexfraction</csymbol>
  <cn type="integer">1</cn>
  <cn type="rational">1<sep/>2</cn>
</apply>
 
where xxx is a document defining the use of the symbol
'complexfraction'. BTW, in OMdoc, you would also put presentation
information there. 

> > 6. When explaining mathematics, it is often useful to present the 
> > different notations used around the world. Is there an attribute or a 
> > markup to specify the cultural domain notation we wish to render?
> > 
> > 
> > Ex.<p>The decimal system of numbers, based on 10, is used in most 
> > countries in the world. The notation for decimal points is not the same 
> > in all countries, however. In Canada and the USA, the point is placed on 
> > the line. In the United Kingdom, it is placed above the line. In France, 
> > a comma is used on the line instead of a point.</p>
> > 
> > p>As a student in France, you would convert the decimal number
> > 	7,12
> >   to a fraction.</p>
> > 
> > <p>In the UK, you would convert the decimal number
> > 	7&middot;12
> >   to a fraction.</p>
> 
> No, not really.  As you obviously know, there is a lot of stuff to do
> in this area, and MML 2 didn't take it on.  For the time being, using
> a private attribute or maybe the 'class' attribute on the <math> tag
> is probably the best work around.

Using the class attribute seems like a hack that does not carry very
far. Again, I think that you can only get around this by styling content
markup with culture-dependent style sheets.

     Michael
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   Dr. Michael Kohlhase,                 School of Computer Science (LTI)
   FB Informatik,  Bau 36, Zi. 220.1     Carnegie Mellon University
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Received on Thursday, 26 April 2001 05:29:46 GMT

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