This is LaTeX code:

[latex]
A(e) = \left[ \begin{matrix} 1 & 2 & 0 & 1 \\ 3 & 0 & -1 & 2 \\ 2 & 5 & 3 & 1 \\ 1 & 2 & 1 & 3 \end{matrix} \right]
[/latex]