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rationals (Re: MathML2 2nd WD (long))

From: Andreas Strotmann <strotman@nu.cs.fsu.edu>
Date: Wed, 12 Jan 2000 10:26:11 -0500 (EST)
To: David Carlisle <davidc@nag.co.uk>
cc: strotman@nu.cs.fsu.edu, www-math@w3.org
Message-ID: <Pine.GSO.4.10.10001120950030.10761-100000@xi.cs.fsu.edu>
> 
> > -- 4.2.2.1/4.4.1.1 Highschool textbooks commonly use float notation for
> > rational numbers (some examples are given in the MathML recommendation).
> > ...Is there an easy way to do this in MathML? 
> 
> you can specify the rational-to-float translation in a stylesheet, or
> you can attach a MathML presentation to a content rational number
> using the semantics element. I am not sure if the answer to your
> question is yes or no. How easy is easy?

Yes, you're using the semantics element in one of the examples in the
text, that's how I noticed that that seemed a little cumbersome for a
standard K-4 math ingredient.  

Using stylesheets doesn't really work all that well, as you will often
need both kinds of representation in the same text.  (Are stylesheet
mechanisms powerful enough to do arbitrary numerical computations to
support rational-to-FP format transformation?)

What I would think simple?  Things like this:

   <cn type="rational"> 1.5 </cn>

or maybe

   <cn type="rational-float"> 1.5 </cn>

which should be fairly uncontroversial.  More difficult to support, and
much more controversial ;-), might be a suggestion like this:

   <cn type="rational"> 0.3&#u+0305; </cn>

where Unicode 0305 is COMBINING OVERLINE and the number represented thus
1/3 in a common lower or middle school notation.

===

While we're discussing <cn>, I think there should be some discussion of
internationalization issues because many Unicode scripts (arabic-indic,
ASCII, eastern arabic-indic, devanagari, bengali, gurmukhi, gujarati,
oriya, tamil, telugu, kannada, malayalam, thai, lao, tibetan, myanmar,
ethiopic, khmer, mongolian, and CJK is what I found in the Unicode 3.0
name list) have their own digits from which many
different languages can make up numbers in math textbooks for k-12 in
their respective languages.

  --  Andreas
Received on Wednesday, 12 January 2000 10:26:28 GMT

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