2.43 Repeat Problem 2.37 for the function f (x1,..., x5) = ), m(1, 4, 6, 7, 9, 10, 12, 15, 17, 19,
20, 23, 25, 26, 27, 28, 30, 31) + D(8, 16, 21, 22).
2.44 Find 5 three-variable functions for which the product-of-sums form has lower cost than the sum-of-products form.