One of the things that is unusual about TeX and LaTeX is that there is
a single character, namely the dollar sign, that is used as an opening delimiter as well as its own
closing delimiter. Moreover, to make things more complicated, two dollar signs in succession are also
viewed as an opening delimiter, with the same succession of two dollar signs as the closing delimiter.
If it hadn't been my ueber-hero Donald Knuth who came up with this, I would have said it's crazy.
Anyway, when using an editor such as Emacs, you have of course high expectations concerning delimiter
matching. But Emacs, by default, is not prepared to handle the kind of thing that TeX does with the
dollar sign. Even in TeX mode, there isn't a lot of intelligence to the $ key. Therefore, I wrote
For more information, see the