1 2 3 4
4 3 2 1
1 3 2 4
3 4 1 2
c1+c2+c3+c4
10 2 3 4
10 3 2 1
10 3 2 4
10 4 1 2
r4-r3,r3-r2,r2-r1
10 2 3 4
0 1 -1 -3
0 0 0 3
0 1 -1 -2
r4-r2
10 2 3 4
0 1 -1 -3
0 0 0 3
0 0 0 1
= 0.
1 2 3 4
4 3 2 1
1 3 2 4
3 4 1 2
c1+c2+c3+c4
10 2 3 4
10 3 2 1
10 3 2 4
10 4 1 2
r4-r3,r3-r2,r2-r1
10 2 3 4
0 1 -1 -3
0 0 0 3
0 1 -1 -2
r4-r2
10 2 3 4
0 1 -1 -3
0 0 0 3
0 0 0 1
= 0.