ref: 45222f41f4256626403a23c33f5c8a7d4ade6d2d
dir: /lib/Control/Arrow.hs/
module Control.Arrow(module Control.Arrow) where first :: forall a b c . (a -> c) -> (a, b) -> (c, b) first f (a, b) = (f a, b) second :: forall a b c . (b -> c) -> (a, b) -> (a, c) second f (a, b) = (a, f b)