trans_t :: Point -> Transform
trans_t p = (trans p, trans p')
   where
      p' = neg p
      neg (x, y, z) = (-x, -y, -z)
trans_t :: Point -> Transform
trans_t p = (trans p, trans p')
   where
      p' = neg p
      neg (x, y, z) = (-x, -y, -z)
trans_t p = (trans p, trans p')
   where
      p' = neg p
      neg (x, y, z) = (-x, -y, -z)