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Re: Transcendental Pi !!

From: Robert Miner <RobertM@dessci.com>
Date: Thu, 28 Oct 2004 10:02:58 -0500
Message-Id: <200410281502.i9SF2wv20933@wisdom.geomtech.com>
To: skvenkat@tnq.co.in
CC: www-math@w3.org


Hi.

> I have some trouble with Presentation MathML specs.
> 
> Under the section:
> 
> 
> 3.2.6.4 Mixing text and mathematics 
> 
> it puts 
> 
> <mo> there exists </mo>
> 
> <mo> such that </mo>
> 
> (so I assume that content decides what tag to put)

This is mostly a theoretical discussion, in my view.  From what I know
of how most people use MathML, and how most MathML-capable software
works, you should probably put things like this in <mtext> tags.

> but at the same time you say:
> 
> <mi>&pi;</mi> (= 3.14...)
> 
> which I feel should be <mn>&pi;</mn> and
> 
> <mn>&ee;</mn>.
> 
> Of course it would be much better if we had an entity like
> 
> &TransendentalPi; (&tpi;).

Remember, this is presentation MathML.  So while one can discuss which
tag most accurately reflects the semantics of the underlying
mathematics, the key thing is whether you want something to *display*
like a variable, a number or text.  The difference between
<mi>&pi</mi> and <mn>&pi</pi> is that you will get an italic pi with
the <mi> and an upright &pi; with the <mn> (at least on systems that
can display both upright and italic greek.)

Similarly, the difference between <mo> such that </mo> and <mtext>such
that</mtext> is that you will get some default operator spacing around
the <mo>, while the <mtext> will be positions tight against the
surrounding constructs.

--Robert

------------------------------------------------------------------
Dr. Robert Miner                                RobertM@dessci.com
W3C Math Interest Group Co-Chair                      651-223-2883
Design Science, Inc.   "How Science Communicates"   www.dessci.com
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Received on Thursday, 28 October 2004 15:03:35 UTC

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