Math & Science ⇒ Two-line Set Definition underneath Sum Operator

[Mr Me]

I want to format properly the formula shown in the attached image. The formula is written within an algorithmic environment, and I can't get the spacing and sizes in the summation right.

The set I want to define for the summation limits would be read: "x in C such that x is in D and x is in E".

Here is my code:

Code: Select all

\begin{algorithm}
   \begin{algorithmic}
      \STATE $a \gets \sum\limits_{ b \in \left\{ x \in C \mid \begin{array}{c} x \in D \\
      \wedge x \in E \end{array} \right\} } b$
   \end{algorithmic}
\end{algorithm}

Any help is greatly appreciated!

[Stefan Kottwitz]

You could use

• \middle| for the middle delimiter "such that"
• subarray of amsmath for a smaller array
• \mathclap of mathtools to not stretch the formula because of the wide array below
• \mathlarger of relsize to get a bigger summation symbol
• perhaps add space before and after the \sum, if \mathclap has been used

Example:

Code: Select all

\documentclass{article}
\usepackage{mathtools}
\usepackage{relsize}
\begin{document}
$a \gets \mathlarger\sum\limits_{\mathclap{ b \in \left\{ x \in C \middle|
  \begin{subarray}{c} x \in D \\
    \wedge x \in E
  \end{subarray}\right\}}} b$
\end{document}

sum.png (3.66 KiB) Viewed 4515 times

Btw. it would be good, in case of problems, to post a compilable minimal working example, as I did here. Then it's easier to provide help - a better chance to get a solution, and faster.

Stefan