C 3. A matter of view - Either or - or what?
And once more back to either-or or exclusive or.
How did it do and where was it useful?
- If A OR B is "1" (but not both), the Z is "1".
So it was used to get the sum of two binary numbers, as odd numbers have the end 1, even numbers end by 0. And when I add two odd numbers the result will be even, adding an even number to an odd number will result in an odd number.
- I can say: If A und B are equal, then is Z = 0. So I can use ist as test for equality.
- But I may also say: If A = 0 Then is Z = B and If A = 1 Then is Z the inversion of B.
B will be inverted, if A=1.
move on