Original sentence: [[\mathbf{A}_{1,1} & \mathbf{A}_{1,2} \\.\ \mathbf{A}_{1,2} \mathbf{B}_{2,2} </math>.\begin{bmatrix}.\end{bmatrix}.\mathbf{A}_{2,1} & \mathbf{A}_{2,2}.\mathbf{B} =
Edited sentence: If the matrices A, B are not of type 2n x 2n we fill the missing rows and columns with zeros.Let A, B be two square matrices over a ring R.We partition A, B and C into equally sized block matrices.We want to calculate the matrix product C as