Can I adjust the symbol "|" in every set?
If we type the below code, the symbol "|" is too small. I know that I can use \big to adjust by manual. Is there a method for automatically adjust?
$\left\{ \sum\limits_{v\in e} f(v) |\ e\in E \right\}$
The extension e-TeX (should be enabled with the LaTeX format) adds \middle to \left and \right. Also the sizes can be manually set using \big and friends. The latter looks nicer, because the index of the summation does not need to be included in the size of the delimiters. Also \bigm sets additional space around the symbol, because it is set as relational operator:
\documentclass{article}
\begin{document}
\[\left\{ \sum\limits_{v\in e} f(v) \middle| e\in E \right\}\]
\[\Bigl\{\sum\limits_{v\in e} f(v) \Bigm| e\in E\Bigr\}\]
\end{document}
|in the first place. Try\Bigm\vert, which will give you the correct amount of horizontal spacing as well. – Mico May 08 '15 at 05:39