“…First, reapply the transformation (8). Second, write every x r, in coordinates of the large-scale system by multiplying it with V from the left:x = V T −1 x * r, (10) In the following, we will refer to this as 'embedding'-step. Third, every system is orthogonally projected into the subspace spanned by the columns of U , which we will subsequently call 'reprojection'-step:…”