liftで遊んでみる。 > :t map map :: (a -> b) -> [a] -> [b] > :t fmap fmap :: (Functor f) => (a -> b) -> f a -> f b > :t liftM liftM :: (Monad m) => (a1 -> r) -> m a1 -> m r > :t liftM2 liftM2 :: (Monad m) => (a1 -> a2 -> r) -> m a1 -> m a2 …