This is LaTeX code:
[latex]
\left( \begin{array}{cccc} -2 & 1 & 0 & 0 \\ 0 & -2 & 0 & 0 \\ 0 & 0 & -2 & 1 \\ 0 & 0 & 0 & -2 \end{array}\right)
[/latex]