Goal, find: ◎ :: (b -> F c) -> (a -> F b) -> (a -> F c)f :: a -> F b, g :: b -> F c:
◎ :: (b -> F c) -> (a -> F b) -> (a -> F c)
f :: a -> F b
g :: b -> F c
(g ◎ f) x
f
x
f x :: F b
g
F b