[XeTeX] Combined sub- and superscript - solved

[Ross Moore]

Hi Peter, Sebastien,

On 08/08/2010, at 7:33 AM, Peter Dyballa <Peter_Dyballa at web.de> wrote:

> 
> Am 07.08.2010 um 22:44 schrieb Sebastian Gerecke:
> 
>> BUT: This just has to be an utter hack and I can not believe it is the way it
>> is supposed to be done.
> 
> This hack is necessary because mhchem is not aware of font features, it's a simple LaTeX package that maltreats simple TeX fonts in the usual ways.
> 
>> I'm putting the scientific inferior numbers in the upper position, and the
>> scientific superiors in the lower position. Does that make sense to anyone?


The usual LaTeX way to do this would be to use the \sideset command from AMSMath, that is with \usepackage{amsmath}.

But this would be placing the usual ASCII numerals, and not using the Unicode inferior and superior numerals. Those characters are very new to the TeX world. A Google search brings up only a few mentions of them on Microsoft pages. Thus you are not likely to find a good solution having easy syntax, until someone writes a macro specially for it, for use with XeTeX and other Unicode-aware TeX processing.

If I've understood this correctly, you want the positioning of \sideset with the characters being the Unicode superiors and inferiors, which are full-sized glyphs. Furthermore, the input syntax should be intuitive, allowing use of either ASCII numerals or the Unicode points directly, for maximum flexibility.

Should such support be in the unicode-math package? 
Probably not, as super-/subscripts in math usually have the usual numerical meaning, so it would be wrong to use separate characters, just for a purely visual effect.

Is a chemist going to learn about Unicode and XeTeX just to typeset isotope names correctly?
We could be so lucky! 

However maybe if someone on this list develops such a macro, it could go into xltxtra.sty .
 

> 
> Well, otherwise it would look much worse...

   Indeed.

> 
> --
> Mit friedvollen Grüßen
> 
>  Pete



Hope this helps,

      Ross