Suppose A has a 0 and B ha a 1 in the current location. |
The hole in the A stream lets the glider from the glider gun stream through, so a 1 is transmitted to B. |
The glider in the B stream is killed by the glider in the glider gun stream, so the current location of A and B is 0. |
That is, if A is 0 and B is one, then A and B is 0. |
Return to the and operation.