### Ellipses

Ellipses are commonly required, and LaTeX natively supplies a fair range (`\``dots`, `\``cdots`, `\``vdots` and `\``ddots`). By using the graphics package, one can change the slope of the `\``ddots` command, as in

      $ ... \reflectbox{$\ddots$} ... $

While this works, it is not a recommended way of achieving the desired result (see below). Moreover, LaTeX’s range is not adequate to everyone’s requirements, and at least three packages provide extensions to the set.

The AMSLaTeX bundle provides a range of “semantically-named” ellipses, for use in different situations: `\``dotsb` for use between pairs of binary operators, `\``dotsc` for use between pairs of commas, and so on.

The yhmath package defines an `\``adots` command, which is the analogue of `\``ddots`, sloping forwards rather than backwards. The yhmath package comes with a rather interesting font that extends the standard cmex; details are in the documentation. The disadvantage of this setup is, that although `\``adots` is merely a macro, the package tries to load its own font and produces a “missing font” substitution warning message if you haven’t installed the font.

The mathdots package (besides fixing up the behaviour of (La)TeX `\``ddots` and `\``vdots` when the font size changes) provides an “inverse diagonal” ellipsis `\``iddots` (doing the same job as yhmath’s `\``adots`, but better).

Documentation of yhmath appears, processed, in the distribution (thus saving you the bother of installing the package before being able to read the documentation). Documentation of mathdots appears at the end the package file itself.

`amslatex`
  macros/latex/required/amslatex (gzipped tar, browse)
`graphics.sty`
  Part of the macros/latex/required/graphics (gzipped tar, browse) bundle
`mathdots.sty`
  macros/generic/mathdots (gzipped tar, browse)
`yhmath (fonts)`
  fonts/yhmath (gzipped tar, browse)
`yhmath (macros)`
  macros/latex/contrib/yhmath (gzipped tar, browse)

This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=mathlips