Write a program where you solve these problems, use recursive functions.

Using haskel

$1.$ Power

Description: Calculate a raised to the power b$.$

Input: Two integers a and b$.$

Output: a raised to the power b$.$

$2.$ Prime numbers less than n

Description: Find all prime numbers less than a positive integer n$.$

Input: A positive integer n$.$

Output: List of prime numbers less than n$.$

$3.$ Length of a list

Description: Calculates the length of a list of elements.

Input: A list of elements.

Output: The number of elements in the list.