How would I go about solving each of these problems?

1. With B being int, and A being real, use same process of the Attribute-Grammar example to analyze statement: B = B + A. Your answer is to include the order of the semantics rules being executed, and the reason why the statement B=B+A is valid or invalid. The following is for the example in slide expected_type actual_type 1. .actual_type - look-up(A) (Rule 4) | 2. .expected_type + .actual_type (Rule 1) 3. [2].actual_type + look-up(A) (Rule 4) [3].actual_type + look-up(B) (Rule 4) 4. .actual_type either int or real (Rule 2) 5. .expected_type == .actual_type is either TRUE or FALSE (Rule 2) actual_type actual_type actual_ty svar>[3] , van> svar>[2] + B . a) Compute the weakest precondition of a = a + 2 * b - 1 {a > 1} b) Compute the weakest precondition of a = 2 * b + 1; = a 3 b {b