ref: e3abe7df7375a8deb2b2f6bc313887e2818c7c26
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)