# right bracket in my TeXworks does not work

I am working in TeXworks and I would like to use [ ] , but when i use \right] , it does not work. What should I do in this regards?when I use just ], there is no space between 2 and ], how should I do it?

for example I have $x = [2, 2]$.

• This is the right way to type, as you are doing: $x=[2,2]$. If you use \right you must use also \left before. Jul 18 '14 at 1:11
• If it is one side , for exapmle $[2, \infty)$ what should I do?
– rose
Jul 18 '14 at 1:13
• Do exactly as you wrote. TeX will insert blank spaces if necessary. Jul 18 '14 at 1:28
• I do not see any reason for using \right in the expression $x=[2,2]$. Jul 18 '14 at 5:38

There is no need to use \right], as the following example shows:

\documentclass{article}
\begin{document}
$x=[2,2]$ $x=\left[2,2\right]$

$x=[2,\infty)$
\end{document}


For denoting a half open interval, the notation with the parenthesis is the most common. If you instead prefer the reverse bracket, which you shouldn't do, use \mathopen and \mathclose:

$\mathopen]a,b]$
$[a,b\mathclose[$
$\mathopen]a,b\mathclose[$


You may have found that \right is to be used in the second case, but you have to remember that \right needs a matching \left before it.