出典:Wikipedia
出典:『Wikipedia』 (2011/04/23 11:31 UTC 版)
Rule 90 is an elementary cellular automaton based on the exclusive or function. It consists of a one-dimensional array of cells, each of which can hold either a 0 or a 1 value; in each time step all values are simultaneously replaced by the exclusive or of the two neighboring values. call it "the simplest non-trivial cellular automaton", and it is described extensively in Stephen Wolfram's 2002 book A New Kind of Science. When started from a random initial configuration, its configuration remains random at each time step; however, any configuration with only finitely many nonzero cells becomes a replicator that eventually fills all of the cells with copies of itself.