Structural Induction with accumulator Consider the functions count' and (++) count' acc - acc - C1 count, acc (x:xs) = count, (1 + acc) xs A1 - A2 [] ++ ys =ys (x:xs) ++ ys = x : (xs ++ ys) Prove by structural induction the following property: count, (count, acc ys) xs = count, acc (ys ++ xs) State clearly what property P is being proved by induction, including any quantifiers needed in the statement of P and in the inductive hypothesis. Structural Induction with accumulator Consider the functions count' and (++) count' acc - acc - C1 count, acc (x:xs) = count, (1 + acc) xs A1 - A2 [] ++ ys =ys (x:xs) ++ ys = x : (xs ++ ys) Prove by structural induction the following property: count, (count, acc ys) xs = count, acc (ys ++ xs) State clearly what property P is being proved by induction, including any quantifiers needed in the statement of P and in the inductive hypothesis