function returned the index of the first occurrence of r in the array A, or -1 if x is not found. Now let's fill in the loop body with code that implements the binary search algorithm (on a sorted array, of course) int search (int x, int[] A, int n) 2 //@requires = x); - + 19 20 @*/ 21 hi = mid; 23 24 //@assert lo == hi; 26 if (lo != n && A[10]-x) return 10; 2 return -1; 28 Prove that, in the case that the code returns on line 18, the postcondition on lines 4-7 always evaluates to true. We've given the starting facts you'll use in this proof. Justify your answers using line numbers or previous steps When we start an iteration of the loop, we know the following: (a) = x); - + 19 20 @*/ 21 hi = mid; 23 24 //@assert lo == hi; 26 if (lo != n && A[10]-x) return 10; 2 return -1; 28 Prove that, in the case that the code returns on line 18, the postcondition on lines 4-7 always evaluates to true. We've given the starting facts you'll use in this proof. Justify your answers using line numbers or previous steps When we start an iteration of the loop, we know the following: (a)