(page 807, problem 23, 3pts ) Let div2(n-Ln/2] (i.e., the largest integer that is less than or equal to n/2). Alternatively, think of it as the function that performs division by 2 on a binary number by shifting right one digit. Prove that the following program correctly multiplies two natural numbers. Clearly state the loop invariant that you are using mult(n, m: natural numbers) result = 0. while m 0 do If odd(m) then result = result + n n=2n. m = div2(m)