2. [6 marks) For this question, I have provided a while loop, a precondition, a postcondition, and a loop invariant. Assume that the loop invariant is true (you do not need to prove it). Prove that the given code satisfies the Partial Correctness property. Algorithm 2 1: //pre: (init is a positive integer) 1 (val == init) 2: //LoopInv: (val > -1)^(both init and val are even integers) V (both init and val are odd integers) 3: while val > 0 do 4: val + val 2 5: end while 6: //post: [(init is even) = (val == 0)] ^ [(init is odd) = (val == -1)]