Programs in the second series were named LCAU to distinguish them from members of the first series. In the original series, in all cases except for , only totalistic rules were considered. Totalistic rules are those for which the transition depends only on the number of cells of different kinds in each neighborhood, but not on their precise arrangement. More exactly, each state gets assigned an integer in the range 0 to k - 1 as a weight, the actual transition being a function of the weighted sum of all the neighbors (including the evolving cell). The artistic effects arise from assigning colors to each of cell values.

Harold V. McIntosh