PassageConsider V=R2V=\mathbb{R}^2 with inner product ⟨(x1,x2),(y1,y2)⟩=x1y1−(x1y2+x2y1)+2x2y2\langle(x_1,x_2),(y_1,y_2)\rangle=x_1y_1-(x_1y_2+x_2y_1)+2x_2y_2.
