[XeTeX] Need some input about \newcommand to create alias

[Alan Munn]

At 11:23 PM -0500 11/27/09, Maxim Cournoyer wrote:
>Dear XeTeX fidels,
>
>In my first document written with XeTeX, I wanted to do an alias for 
>the abbreviation CO_2 (carbon dioxyde), but had two difficulties.
>
>My first one was to try to use something like this : 
>%\newcommand{\co2}{CO$_2$}
>The problem was that it seems we cannot use "numbers" in the command 
>name, such as the '2' in \co2. Is there a way to circumvent this?

Not really. Numbers aren't allowed in macro names.

>
>Another weird issue I ran into was, after changing  \co2 to 
>something more wordy as \codeux, my actual replacement would delete 
>all trailing space. Let me explain by an example :
>ex : The traffic in developed nations  is the cause to an average of 
>26% of the \codeux emissions.
>
>Results : The traffic in developed nations  is the cause to an 
>average of 26% of the CO_2emissions.
>
>Note the lack of a space character between the _2 subscript and 
>emissions. Using CO$_2$ straight in my text solved the problem, 
>surprisingly. Is there an explanation for this?

Yes, commands gobble the spaces after them.

>  What should I do to prevent this from happening?

Two solutions:

\newcommand{codeux}{CO$_2${}}

or

\usepackage{xspace}
\newcommand{codeux}{CO$_2$\xspace}


Alan

P.S. Neither of these questions is actually related to xetex.  You 
might want to check the TeX FAQ, and get a good introduction to 
LaTeX.  Or post your questions to the comp.text.tex newsgroup.

http://www.tex.ac.uk/cgi-bin/texfaq2html?introduction=yes


-- 
Alan Munn						amunn at msu.edu
Department of Linguistics
and Germanic, Slavic, Asian and African Languages		Tel. 
	517-355-7491
Michigan State University, East Lansing MI 48824 USA	Fax	517-432-2736