+---+--+---+ +---+---*---+ __ /1Y |1 +--+ 14| VCC | A | B |/Y | /Y = AB 1A |2 13| /4Y +===+===*===+ 1B |3 12| 4B | 0 | 0 | Z | /2Y |4 7401 11| 4A | 0 | 1 | Z | 2A |5 10| /3Y | 1 | 0 | Z | 2B |6 9| 3B | 1 | 1 | 0 | GND |7 8| 3A +---+---*---+ +----------+