8.

Consider the function

palindrome xs = reverse xs == xs

What is its type? (5 points). Why are there the particular class

constraints on "xs"? (5 points)

9.

Consider the function

twice f x = f (f x)

What is its type? (5 points). What constraints does "twice" place on

the type that function "f" can be? (5 points)

Hint: try seeing what happens when we call "twice head [1,2,3]" in

GHCi