Only 2 conditions: positive + positive = negative -> bit overflow negative + negative = positive -> bit overflow
For: positive + negative -> won’t ever overflow In the worst case: max_positive + max_negative = max_positive + 0 = max_positive
The magnitude range: 0 <= positive + negative <= max_positive
Same as 1s-complement
A = -7 = 1001 B = -6 = 1010
result = -13 = 1 0011
It is clear that there is overflow here.