two 2's complement nos. having sign bits x and y are added and the sign bit of result is z. Then the occurrence of overflow is indicated by the expression???
The answer is given as x'y'z + xyz' .
As far as I know, Overflow is indicated by Cn XOR C(n-1).
So, here Cn is 'z' and C(n-1) is x+y . Whose XORing gives me.. x'y'z + xz' + yz'.