Type Inference

map ::	(a -> b, [a]) -> q
f ::	a -> b
h ::	a
t ::	[a]

"f must take an argument of type a and return a result of type b."

        map(f, []) = []
        map(f, h:t) = f(h) : map(f, t)

"The result of f is consed to the result of map."