\begin{Schunk}
\begin{Sinput}
 Sigma
\end{Sinput}
\begin{Soutput}
     [,1] [,2] [,3] [,4]
[1,]  1.0  1.0  4.2  2.8
[2,]  1.0  4.0 -1.4  0.8
[3,]  4.2 -1.4 49.0  5.6
[4,]  2.8  0.8  5.6 16.0
\end{Soutput}
\end{Schunk}
