1MS : 2.5.21 r

[ 1, -1,  1,  0]
[-1,  1,  1, 10]
[ 1,  1, -1,  2]

L_2 <- L_2 + 1 * L_1

[1, -1,  1,  0]
[0,  0,  2, 10]
[1,  1, -1,  2]

L_3 <- L_3 - 1 * L_1

[1, -1,  1,  0]
[0,  0,  2, 10]
[0,  2, -2,  2]

L_3 <- L_3 - 1 * L_2

[1, -1,  1,  0]
[0,  0,  2, 10]
[0,  2, -4, -8]

L_2 <-> L_3

[1, -1,  1,  0]
[0,  2, -4, -8]
[0,  0,  2, 10]

L_2 <- 1/2 * L_2

[1, -1,  1,  0]
[0,  1, -2, -4]
[0,  0,  2, 10]

L_3 <- 1/2 * L_3

[1, -1,  1,  0]
[0,  1, -2, -4]
[0,  0,  1,  5]