0 0 z a
0 0 z+1/2 a
1/2 1/2 z b
1/2 1/2 z+1/2 b
0 1/2 z c
1/2 0 z+1/2 c
0 1/2 z+1/2 c
1/2 0 z c
x x z d
-x -x z d
-x x z+1/2 d
x -x z+1/2 d
x y z e
-x -y z e
-y x z+1/2 e
y -x z+1/2 e
x -y z+1/2 e
-x y z+1/2 e
-y -x z e
y x z e