-3 3 setxrange
-1 3 setyrange
25 setxunit
3 10 6 SetCamPos
0 0 0 SetCamView
qplanxy
0 1 1 axesRVB
2 setlinejoin 
/table [-1 -1 1 -1 0 1] def 
table 0 2 genereprismedroit
{2 0 0 translatepoint3d} solidtransform
drawsolid
table 0 2 -.25 -.25 1 genereprisme
{-2 0 0 translatepoint3d} solidtransform
drawsolid