// \(0\)と\(1\)のみを成分とする\(2 \times 3\)行列\(A\)で， \(\displaystyle {A}\,{^t\!A} = \left ( \begin{array}{cc} 1 & 0 \\ 0 & 2 \end{array} \right ) \)，\(\displaystyle {^t\!A}\,{A} = \left ( \begin{array}{ccc} 1 & 0 & 0 \\ 0 & 1 & 1 \\…