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Re: mover vs latin chars with diacriticals

From: Neil Soiffer <neils@dessci.com>
Date: Fri, 28 Apr 2006 11:22:55 -0700
Message-ID: <D1EFB337111B674B8F1BE155B01C6DD60DB798@franklin.corp.dessci>
To: "Public MathML mailing list" <www-math@w3.org>
----- Original Message ----- 
> From: <juanrgonzaleza@canonicalscience.com>

<snip>
 
> I obtained the range 0300-036F Unicode standard (MathML is not a standard
> and standards may be preferred over not ones) and searched for "x-dot"
> (i.e. for "combining dot above"). The Unicode value is 0307.
> 
> Just in the first line of the description of the code says
> 
> "= Derivative (Newtonian notation)"
> 
> Let me remark that there is a "="
> 
> The standard also notes relationship with Unicode 02D9 (dot above also but
> *not* in math section).

"=" means it is an informative comment.  Standards have informative comments and normative statements.  Informative comments are *not* part of the standard.  The informative comment says this can be used for the newtonian derivative notation, not that it should be used.

Citing STIX fonts as having pre-composed diacriticals is irrelevant.  Precomposed characters  (as noted by some of the places you quote and the Unicode standard) can provide a better rendering.  However, they are a rendering technique and there is no reason a smart MathML renderer shouldn't substitute those glyph's for <mover> *if* they are available.  At the current point in time, that is a big if.  If you try the following in IE, you'll see that the later two blocks do not render (at least on my machine):
<p> Extended A:  <em>&#x0100;&#x0101;&#x102;&#x103;</em></p>
<p> Extended B:  <em>&#x0200;&#x0201;&#x202;&#x203;</em></p>
<p> Extended Additional:  <em>&#x1E00;&#x1E01;&#x1E02;&#x1E03;</em></p>
Firefox (on my machine) does render it properly.

Although dotted versions of the characters exist in Unicode for all of the roman letters, they don't exist for Greek letters or for other alphabets.  For these, you must use "combining dot above".

> [http://www.geocities.com/chavchan/userjs/support.xml]
> 
>Support for ANSI/NISO/ISO-12083 Mathematics DTD
>
> "Overscripts should not be used to produce accents, Unicode based
> solutions (either combining diacritical marks, or precomposed characters)
>  are preferable in this case."

This is one person's opinion, not what ISO-12083 says.  As far as I could see, 12083 is silent on the matter.  While it is informative to get another opinion on this, implying that this is what 12083 says is false (at least as far as I could see in 12083's math section).

Neil Soiffer
Senior Scientist
Design Science, Inc.
www.dessci.com
~ Makers of Equation Editor, MathType, MathPlayer and MathFlow ~

Received on Friday, 28 April 2006 18:23:12 GMT

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