A Reversible NAND Gate

The great discovery of Bennett and, independently, of Fredkin is that it is possible to do computation with a different kind of fundamental gate unit, namely, a reversible gate unit. I have illustrated their idea--with a unit which I could call a reversible NAND gate. It has thre inputs and thre outputs. Of the outputs, tow, A' and B', are the same as two of the inputs, A and B, but the third input works this way. C' is the same as C unless A and B are both 1, in which case it changes whateve...