[XeTeX] unicode-math package and \UnicodeMathSymbol command
Ross Moore
ross at ics.mq.edu.au
Mon Jun 22 04:48:23 CEST 2009
Hi Joel,
On 22/06/2009, at 12:05 PM, Joel C. Salomon wrote:
> Ross Moore wrote:
>> Indeed I think that it is wrong to have this
>> in unicode-math-add.tex :
>>
>> \UnicodeMathSymbol{"0003A}{\colon}{\mathpunct}{}%
>>
>> especially so since unicode-math.tex already has this:
>>
>> \UnicodeMathSymbol{"02236}{\colon}{\mathrel}{ratio}
>>
>> which follows AMS usage, but which differs from the original \TeX .
>>
>> It is most unfortunate that, over the years, there has been
>> a lot of confusion about the use of \colon and : .
>> It's not at all clear how this should be sorted out now.
>> Probably it depends upon what font designers have chosen to do.
>
> This is an issue Will knows about; see the GitHub bug tracker at
> <http://github.com/wspr/unicode-math/issues/#issue/7>. It’s the
> Unicode
> folks, not font designers, that have decided the issue (somewhat):
> ‘:’
> [U+003A] is called “Colon”, the punctuation mark, while
> ‘∶’ [U+2236] is
> the “Ratio” relation symbol.
By giving them different names they have done something good!
> BTW, I’m not sure what you mean by AMS usage differing from the
> original
> TeX; both the “Short Math Guide” and the amsmath package
> documentation
> say that ‘:’ has relation spacing and ‘\colon’ is for
> punctuation, /à
> la/ the TeXBook.
I was looking at the line in the STIX table:
02236 uni2236 EE34 2DR R ratio ISOAMSR P\colon Colon r000
0x2236 6 3B ratio
which seems to indicate that \colon is meant to be the macro for this
symbol, from the ISO-AMS relations block of characters.
I believe this is the reason why it is wrong in unicode-math.tex .
The later loading of unicode-math-add.tex does nothing to fix it.
>
> It seems that, somewhat counter-intuitively, ‘:’ [U+003A] ought
> to be a
> synonym for the mathrel ‘∶’ [U+2236], and ‘\colon’ must be
> used to
> include the actual [U+003A] mathpunct.
The logic, as I understand it, is that when in a math environment,
the ':' symbol is normally used with relation spacing;
e.g., as a substitute notation for \mid with a set of elements
subject to a condition.
(In this setting the ':' symbol should not be thought of as a colon,
but as an abbreviation for 'such that' or somesuch.)
If you want a visual effect more akin to a colon in text punctuation,
then use the macro \colon .
In other words \colon and ':' are *not* meant to be alternative ways
of getting the same result. (i.e., *not* the same LICR, in that jargon).
For function notation, roughly f: A -> B (in ASCII only)
what I use in serious publications is something like:
\let\from\colon % in the preamble
$ f\from A\to B $
which reads pretty much as you would say it.
>
> —Joel Salomon
Cheers,
Ross
------------------------------------------------------------------------
Ross Moore ross at maths.mq.edu.au
Mathematics Department office: E7A-419
Macquarie University tel: +61 (0)2 9850 8955
Sydney, Australia 2109 fax: +61 (0)2 9850 8114
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