2 0 3 1
3 0 4 -3
等於
(1 0 2 -1)
0 0 -1 3
0 0 -2 0
(1 2 -1 0)
0 -1 3 0
0 -2 0 0
0 1 -3 0
(1 0 5 0)
0 0 -6 0
0 0 1 0
(1 0 0 0)
0 1 0 0