The affine group is [4,3,4] (), can be given by four reflection matrices. Mirror R 0 can be put on z=0 plane. Mirror R 1 can be put on plane y=z. Mirror R 2 can be put on x=y plane. Mirror R 3 can be put on x=1 plane. [4,3,4] () is generated by S 0,1, S 1,2, and S 2,3.