# Square brackets instead of curvy brackets

I have the following example:

$$$\left \{ \begin{tabular}{cccc} 1 & 5 & 8 & a \\ 0 & 2 & 4 & a \\ 3 & 3 & -8 & a \end{tabular} \right \}$$$


It should be a matrix, so I would like to have proper square brackets. I have tried the approach with setting them manually (\Bigg[) but the matrix is going to be larger so it needs to be set automatically. In the code above, I tried to use:

 $\left \[  but it didn't work. Any idea what's not working in the previous code? • \left[ and \right]. The characters { and } are special, so the must be escaped for getting printed braces, but [ and ] aren't special. However, with the package amsmath you can simply type \begin{bmatrix} 1& 5 & 8 & a \\...\end{bmatrix}. – egreg May 18 '15 at 17:38 ## 1 Answer There are many expanding delimiters available in TeX/LaTeX; the main ones are (round) parentheses, (square) brackets and braces. The only problematic ones among them are the braces, because { and } are special characters, used for grouping and for delimiting arguments. So, \left(...\right), \left[...\right] and \left\{...\right\} are the “automatically expandable versions. The same for the manual \bigl(, \bigl[ and \bigl\{; similarly for \bigr and the other commands in the same family. The commands \[ and $ mean a totally different thing: they delimit an unnumbered math equation.

So your case should be (with array, not tabular):

$$\left[ \begin{array}{cccc} 1 & 5 & 8 & a \\ 0 & 2 & 4 & a \\ 3 & 3 & -8 & a \end{array} \right]$$


but upon loading amsmath you have a wealth of better constructions:

$$\begin{bmatrix} 1 & 5 & 8 & a \\ 0 & 2 & 4 & a \\ 3 & 3 & -8 & a \end{bmatrix}$$