  [Gacs, Kurdiumov, Levin, 78] proposed simple one-dimensional cellular
automata with 2 states. In an infinite array they are self-stabilizing: if all
but a finite minority of automata are in the same state, the minority states
disappear. Implicit in the paper was a stronger result that a sufficiently
small minority of states vanish even in a finite circular array. The following
note makes this strengthening explicit.
