Name (print) ___________________________________   Lab Section you attend______________

CSE131 Module 3 Extension
Iteration
Take-home, due 25 Sept 2008 in Lab

Consider the iterative method below: 
// return the product of a and b, which must be supplied as positive integers.
public static int mpy(int a, int b) {

   int ans = 0,
         i = b;

   while (i != 0) {

       i = i - 1;

       ans = ans +  a;

   }

   return ans;
}

Develop and use a loop invariant to prove that the method computes the appropriate product. You may interact only with the professor on this problem (by IM or in person). You must be able to explain your proof in person during Lab or Studio session to the professor.