1. What are the types of the following: a) fun ex1 a b c = (a,b)::c; b) fun ex2 f (a,b) = (f a, f b); c) fun ex3 f g (a,b,c) = g (f a, f b, f c); d) fun ex4 f [] = [] | ex4 f (a::b) = (f a)::(ex4 f b);