12. This N = 3 rule is equivalent to the N = 2 rule of problem 1. Regardless of the
left cell, we want center live and right dead to give a live cell. In terms of N = 3 this
means dead-live-dead and live-live-dead give a live cell. Similarly,
regardless of the left cell, we want center dead and right live to give a live cell. In
terms of N = 3 this means dead-dead-live and live-dead-live give
a live cell.
