For these problems, use the following implementation of unfold: def unfold [A, S](z: S)(f: S => Option[(A, S)]): LazyList[A] = f(z) match { case Some((h, s)) => h #:: unfold(s)(f) case None => LazyList() [Note: #:: is the Cons constructor of LazyLists] Problem 1 [10 + 10 Points] Define a LazyList to generate an infinite list of prime numbers. Use higher-order functions whenever possible. Solve this problem (a) using unfold, and (b) without using unfold