W:=Matrix([[1.01,0.99,1,1.1],[1,1,1,0.98],[1,1,1,1],[1,1,1,1]]);
> P1:=Matrix(4, 4, {(1, 1) = [9/16, -45/64, -5/4], (1, 2) = [9/16, -45/64, -5/12], (1, 3) = [9/16, -45/64, 5/12], (1, 4) = [9/16, -45/64, 5/4], (2, 1) = [-73/48, 455/192, -5/4], (2, 2) = [-73/48, 455/192, -5/12], (2, 3) = [-73/48, 455/192, 5/12], (2, 4) = [-73/48, 455/192, 5/4], (3, 1) = [-73/48, -455/192, -5/4], (3, 2) = [-73/48, -455/192, -5/12], (3, 3) = [-73/48, -455/192, 5/12], (3, 4) = [-73/48, -455/192, 5/4], (4, 1) = [9/16, 45/64, -5/4], (4, 2) = [9/16, 45/64, -5/12], (4, 3) = [9/16, 45/64, 5/12], (4, 4) = [9/16, 45/64, 5/4]});
> P2:=Matrix(4, 4, {(1, 1) = [-1, 2, -5/4], (1, 2) = [-1, 2, -5/12], (1, 3) = [-1, 2, 5/12], (1, 4) = [-1, 2, 5/4], (2, 1) = [-1/3, 0, -5/4], (2, 2) = [-1/3, 0, -5/12], (2, 3) = [-1/3, 0, 5/12], (2, 4) = [-1/3, 0, 5/4], (3, 1) = [1/3, -2/3, -5/4], (3, 2) = [1/3, -2/3, -5/12], (3, 3) = [1/3, -2/3, 5/12], (3, 4) = [1/3, -2/3, 5/4], (4, 1) = [1, 0, -5/4], (4, 2) = [1, 0, -5/12], (4, 3) = [1, 0, 5/12], (4, 4) = [1, 0, 5/4]});