Below is the pseudocode for exponentiation by squaring. Precondtion: n greaterthanorequalto 0 int power (int m, int n) {int x = m; int y = n; int result = 1; while (y is notequalto 0) {if (y is even) x = x * x; y = y/2;} else {result = result * x; y = y - 1;}} return result;} Postcondition: result = m^n Assume that the loop invariant is m^n = result * x^y. Show that 1) the invariant holds before the loop (base case), 2) assuming invariant holds after k-th iteration, and execution takes a k+1-st iteration, the invariant still holds (inductive step), 3) the loop exit condition and the loop invariant imply the postcondition result = m^n. Find a suitable decrementing function. Prove that the function is indeed a decrementing function