reduceSize (D s)         = case (reduceSize s) of
                             Min -> Min
                             s'   -> D s'
reduceSize (D s)         = case (reduceSize s) of
                             Min -> Min
                             s'   -> D s'
reduceSize (D s)         = case (reduceSize s) of
                             Min -> Min
                             s'   -> D s'