Re: port x-symbol to GNU emacs 24.

   > Uwe wrote in response to Stephen:

   > Has it occurred to you to do a web search?

Yes.

   > In summary, if you want to do Unicode maths properly (or Unicode
   > anything else properly), you should really switch to Xe(La)TeX.

I am using Xelatex on a regular base, basically for hebrew. I presume
you mean by unicode math, the following package

\usepackage{fontspec,unicode-math}

That however requires special fonts, standard as it seems for TeXlive
2011, but not necessarily standard in older distributions. So if you
wish to send a file with utf8 math symbols to a colleague (as I do
frequently) you might run into a problem.


   > If you don't want to do that (and it's not entirely trivial), you can
   > hack things with [uft8x]inputenc and mathletters.

The same comment applies to mathletters.


In short the advantage of x-symbol over utf8 math symbol is:

    -  it produces standard Latex which is compatible back even versions
       prior to Latex2e.

    -  the x-symbols are much nicer than the utf-8 ones.