# Getting items above and below a compound math symbol

I'm trying to get information to appear above and below a math symbol such as \sum or \leftrightarrows. I've found information detailing \mathop and the syntax behind it but when I try to use it, it appears my tex editor doesn't recognize it as a command. Is mathop not in the ams math package?

I'm a relatively new latex user so any help would be appreciated.

The tutorial I'm following is http://truonglatex.wordpress.com/2010/04/13/arrows-and-stack-math-symbols/

My output looks as the attached image. The code is identical to the one on the website.

Thanks any help would be appreciated.

• \sum\limits... – user11232 Nov 12 '14 at 1:34
• The user guide of the amsmath package may be opened by typing texdoc amsmath at a command prompt. The macro \mathop (note the initial backslash character) is built into TeX's language; it's not provided by the amsmath package. – Mico Nov 12 '14 at 6:44

Without MWE (Minimal Working Example) we can guess, how you used the code, but we cannot, how you want to, hence two cases.

\documentclass{article}
\usepackage{amsmath}

\begin{document}

You have

$a\mathop{\sum\sum\sum}_{a=\frac12}^{\text{some text}}b$

You want to

$a\mathop{\sum\sum\sum}_{a=\frac12}^{\text{some text}}b$

If you want it in inline mode, use \verb+\limits+
$a\mathop{\sum\sum\sum}\limits_{a=\frac12}^{\text{some text}}b$

\end{document}
`

• Thanks a lot for the speedy response. That's exactly what I needed! Cheers. – tangosierra Nov 12 '14 at 2:22