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Re: consistency of 2007doc entities and Unicode Technical Report#25

From: <w3@karlt.net>
Date: Thu, 31 Jan 2008 19:24:58 +1300
CC: davidc@nag.co.uk
To: www-math@w3.org
Message-ID: <877ihqa4w5.fsf@karlt.net>

Thanks for looking into this David, and for your explanations.

>> jmath
>
> This is mapped to the base plane partly for compatibility with imath
> and partly for better functionality with mathml's mathvariant attribute.
> imath ...
> I think there are some benefits in mapping it to the base plane.
> <mi mathvariant="bold">x</mi> (for any variant)
> is defined as a Unicode to Unicode mapping, you take the base character
> and define the construct as being equivalent to the Unicode specified
> mathematical bold character. If you put a styled character in the mi in
> the first place mathvariant isn't supposed to have any effect.
> So my understanding is that with jmath defined as it is, 
> <mi mathvariant="bold">&jmath;</mi>
> is a bold dotless j, but if jmath mapped to 1D6A4 then it would not be.
> (Same argument for imath of course) Now MathML3 could change the rules
> but that's my understanding of the rules for  MathML2.

Although my initial thoughts on this were that this sounded
something to be taken into account, after more consideration, I'm
not so sure.

IIUC MathML2 intends mathvariant only for Unicode to Unicode mappings
(because some/many applications weren't designed to handle SMP
characters), not for applying style.

http://www.w3.org/TR/2003/REC-MathML2-20031021/chapter3.html#presm.commatt

 "It is important to note that only certain combinations of
  character data and mathvariant attribute values make sense.
  ...
  By design, the only cases that have an unambiguous
  interpretation are exactly the ones that correspond to SMP Math
  Alphanumeric Symbol characters, which are enumerated in Section
  6.2.3 Mathematical Alphanumeric Symbols Characters. In all other
  cases, it is suggested that renderers ignore the value of the
  mathvariant attribute if it is present."

This provides that <mi>&infin;</mi>, for example, does not have any
slant applied.

Renderers following this suggestion would not currently render
<mi>&#x0131;</mi> LATIN SMALL LETTER DOTLESS I with an italic
style.

Karl.
Received on Thursday, 31 January 2008 06:26:57 GMT

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