As we all know, there are many equation environments to choose, including

  • equation
  • multline
  • align
  • eqnarray
  • IEEEeqnarray

I prefer

  • $$ for inline equation
  • equation for single-line equation
  • IEEEeqnarray for multi-line equation and equations

To use IEEEeqnarray, you should install IEEEtran, which can be downloaded at

On Arch Linux, using texlive, I just use texconfig -> CONF to find the path of TEXMFLOCAL, and make a folder TEXMFLOCAL/tex/latex/IEEE and copy all the files in that folder. Finally, run texhash.

You should add this line in the preamble of your LaTeX file


To add an IEEEeqnarray, use