Single-argument doesn't capture the difference between functor and applicative. ex1 :: Functor f => f (Int, Int) -> f Int ex1 = map (uncurry (+)) Applies

Single-argument doesn't capture the difference between functor and applicative. ex1 :: Functor f => f (Int, Int) -> f Int ex1 = map (uncurry (+)) Applies a multi-argument function within a functor. What applicative allows you do is take a product of contexts to a context of products, and lift a value to a context. pure :: a -> f a zip :: (Applicative f) => (f a, f b) -> f (a, b) This can then be used to make ex1 into a multi-argument function of contexts, which is not the same as (uncurry (+)) being a multi-argument function ex2 :: (Functor f) => (f Int, f Int) -> f Int ex2 = ex1 . zip