[−10−121]\left[\begin{array}{cc}-1 & 0 \\-\frac{1}{2} & 1\end{array}\right][−1−2101]
[10−12−1]\left[\begin{array}{rr}1 & 0 \\-\frac{1}{2} & -1\end{array}\right][1−210−1]
[−1−1201]\left[\begin{array}{rr}-1 & -\frac{1}{2} \\0 & 1\end{array}\right][−10−211]
[1−120−1]\left[\begin{array}{rr}1 & -\frac{1}{2} \\0 & -1\end{array}\right][10−21−1]
