2. Consider 2's complement 4-bit signed integer addition and subtraction. Since the operands can be negative or positive and the operator can be subtraction or addition, there are 8 possible combinations of inputs. For example, a positive number could be added to a negative number, or a negative number could be subtracted from a negative number, etc. For each of them, describe how the overflow can be computed from the sign of the input operands and the carry out and sign of the output. Fill in the table below: Sign (Input 1) Sign (Input 2) Operation + + Sign (Output) Overflow (Y/N) + + + + + + + + + + + + + + - + + + + + + . + + + + + + + + +