# Using symbol “{” in big size

I want to use to symbol { in big size and I tested $\left\{$ but it is not functional. So, I need to help for writing this symbol.

• Did you try \left\{ along with a matching \right\} or \right.? If that does not solve your problem, it would be helpful if you composed a fully compilable MWE including \documentclass and the appropriate packages that sets up the problem. – Peter Grill May 13 '15 at 22:31

\left needs an accompanying \right (within the same group) in order for it to work as expected. The null delimiter . could be used to provide an accompaniment that shouldn't be printed (and may require some spacing correction).

For fixed-height sizes, you can use \big, \Big, \bigg or \Bigg. Extensible delimiters require \left (or \mleft):

\documentclass{article}
\usepackage{amsmath,mleftright}
\begin{document}

Fixed-height \verb|{|:
$\big\{ \quad \Big\{ \quad \bigg\{ \quad \Bigg\{$

Extensible \verb|{|:
$\mleft\{ \rule{0pt}{5\baselineskip}% Strut, or whatever \mright.$

\end{document}


Typically \big-related scaling is used in a \bigl-\bigr context rather than just \big (for spacing purposes).

If you need the curly braces to stay "curvy" even if they're quite large, you may want to look into using the mtpro2 package and its \LEFTRIGHT macro. The smallest curly brace, on the left, is generated by \{; the largest curly brace is more than 5 cm tall! Note that all braces are "curvy", which is not the case if one uses \left\{... to generate them.

\documentclass{article}
\usepackage{mtpro2}
\begin{document}
$\{ \Bigg\{ \LEFTRIGHT\{.{\vphantom{\xl\sum}} \LEFTRIGHT\{.{\vphantom{\XL\sum}} \LEFTRIGHT\{.{\vphantom{\XXL\sum}} \LEFTRIGHT\{.{\vphantom{\XXXL\sum}}$
\end{document}