# Conway's Game of Life is the classic cellular automaton.

;; see http://en.wikipedia.org/wiki/Conway's_Game_of_Life

;; This ruleset works with any strictly black and white map, but the maps which
;; are designed to work with it have names starting 'life'.
 
;; The universe of the Game of Life is an infinite two-dimensional orthogonal 
;; grid of square cells, each of which is in one of two possible states, alive 
;; or dead, represented in this ruleset by 'black' and 'white' respectively. 
;; Every cell interacts with its eight neighbours, which are the 
;; cells that are horizontally, vertically, or diagonally adjacent.

;; Although this ruleset is superficially simple, it runs very slowly, because
;; all the rules depend on neighbours, which makes them more expensive to
;; compute.

;; At each step in time, the following transitions occur:

;; Any live cell with fewer than two live neighbours dies, as if caused by 
;; under-population.

if state is black and fewer than 2 neighbours are black then state should be white

;; Any live cell with two or three live neighbours lives on to the next generation.

;; Any live cell with more than three live neighbours dies, as if by overcrowding.

if state is black and more than 3 neighbours are black then state should be white

;; Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.

if state is not black and 3 neighbours are black then state should be black

# Initialisation rules

if state is new and altitude is more than 127 then state should be black

if state is new then state should be white