[1−102]\left[\begin{array}{rr}1 & -1 \\0 & 2\end{array}\right][10−12]
[2101]\left[\begin{array}{ll}2 & 1 \\0 & 1\end{array}\right][2011]
12[2−101]\frac{1}{2}\left[\begin{array}{rr}2 & -1 \\0 & 1\end{array}\right]21[20−11]
12[2101]\frac{1}{2}\left[\begin{array}{ll}2 & 1 \\0 & 1\end{array}\right]21[2011]