Yes, <$> is the general `map` (`fmap`) <*> takes function(s) out of a mappable and applies it (them) to argument(s) within a mappable. (+) <$> [1,2,3] =

Yes, <$> is the general `map` (`fmap`) <*> takes function(s) out of a mappable and applies it (them) to argument(s) within a mappable. (+) <$> [1,2,3] = [add 1, add 2, add 3] (+) <$> [1,2,3] <*> [10, 20] = [(1 +), (2 +), (3 +)] <*> [10, 20] = [11, 21, 12, 22, 13, 23] (+) <$> Just 3 <*> Just 5 = Just (3 + ) <*> Just 5 = Just 8 (+) <$> readLn <*> readLn = ... well that depends on the inputs :)