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Re: [XML-Entities] Question regarding some Unicode sequences

From: David Carlisle <davidc@nag.co.uk>
Date: Wed, 21 May 2014 21:05:25 +0100
Message-ID: <537D0705.2010008@nag.co.uk>
To: William F Hammond <hammond@csc.albany.edu>, <www-math@w3.org>
On 21/05/2014 20:55, William F Hammond wrote:
>>> I noticed that the Unicode sequences of more than one
>>> codepoints are assigned to some entities which already
>>> had single Unicode codepoints representation at the time
>>> of addition to MathML; e.g. "race" entity from isoamsb
>>> set is mentioned as U+223D U+0331 (REVERSED TILDE,
>>> COMBINING MACRON BELOW) while it can also be presented as
>>> U+22CD. Is there any specific reason for this preference?
>> While I think it _could_ have been defined the way you
>> suggest I don't think it should change now, it's been that
>> way in mathml (and now html) for a long time, and 22CD, if
>> you need it, already has two names bsime (from isaomsr)
>> and backsimeq so adding a third name for that symbol
>> wouldn't really help much and just lead to incompatible
>> definitions being used.
> U+0331 is a combining character.  It's use with U+223D leads
> to an image in my present Firefox with my default fonts that
> is too small, too far below the reversed tilde, and not
> centered below the reversed tilde.


Support for combining characters in browsers has been historically 
"variable"
you should be happy that the line combines at all:-)

>   U+22CD is much better.

Sure, but you can use &#x22CD; or &bsime; or ⋍ to get that character
changing &race; now wouldn't really help, even if updating the list is 
possible.

>
> (I don't see the reference to "race" as an entity name although
> I do see something in isoamsb.ent [MathML2 materials] pointing
> to U+E40C in Unicode private space.)

Not sure where you were looking? It's in the entities spec here

http://www.w3.org/TR/xml-entity-names/isoamsb.html

>
>                                      -- Bill

David
Received on Wednesday, 21 May 2014 20:05:58 UTC

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