+---+--+---+ +---+---*---+ ___ 1A |1 +--+ 14| VCC | A | B |/Y | /Y = A+B 1B |2 13| 4B +===+===*===+ /1Y |3 12| 4A | 0 | 0 | 1 | /2Y |4 4001 11| /4Y | 0 | 1 | 0 | 2A |5 10| /3Y | 1 | 0 | 0 | 2B |6 9| 3B | 1 | 1 | 0 | GND |7 8| 3A +---+---*---+ +----------+