(CubePoints f1 f2 f3 f4 b1 b2 b3 b4) +++ (TopFace b2t f2t b3t f3t) =
   (BottomFace {b1=b2, b4=b3, f1=f2, f4=f3}) +++ (TopFace b2t f2t b3t f3t)
(CubePoints f1 f2 f3 f4 b1 b2 b3 b4) +++ (TopFace b2t f2t b3t f3t) =
   (BottomFace {b1=b2, b4=b3, f1=f2, f4=f3}) +++ (TopFace b2t f2t b3t f3t)
(CubePoints f1 f2 f3 f4 b1 b2 b3 b4) +++ (TopFace b2t f2t b3t f3t) =
   (BottomFace {b1=b2, b4=b3, f1=f2, f4=f3}) +++ (TopFace b2t f2t b3t f3t)