myCycle :: [a] -> [a]
myCycle l0 = foldr step l0 [l0]
  where
    step l _ = l ++ myCycle l
myCycle :: [a] -> [a]
myCycle l0 = foldr step l0 [l0]
  where
    step l _ = l ++ myCycle l
myCycle l0 = foldr step l0 [l0]
  where
    step l _ = l ++ myCycle l