rescale :: Int -> CycleStructure -> CycleStructure
rescale k pi
  | k `notElem` concat pi = pi
  | otherwise = map rescale' pi where
    rescale'  = map (\i -> if i >=k then i + 1 else i)
rescale :: Int -> CycleStructure -> CycleStructure
rescale k pi
  | k `notElem` concat pi = pi
  | otherwise = map rescale' pi where
    rescale'  = map (\i -> if i >=k then i + 1 else i)
rescale k pi
  | k `notElem` concat pi = pi
  | otherwise = map rescale' pi where
    rescale'  = map (\i -> if i >=k then i + 1 else i)