(Color online) Critical value of ( as a function of the parameter ) on different square lattices.

<p>(a) Results on the square lattice with 4-player neighborhood and synchronous updating; (b) Results on the square lattice with 8-player neighborhood and synchronous updating; (c) Results on the square lattice with 4-player neighborhood and asynchronous updating; (d) Results on the square lattice with 8-player neighborhood and asynchronous updating.