\ cellular automata in ck;

[8 2 # swap vs |:]				`rule 	def	\ 30 rule;
[dup 2 * &: 1 , !] 				`start 	def	\ 3 start -> 1 1 1 0 1 1 1;
[2 [0 , |:] do]					`sheet 	def	\ sheet;
[dup [*: [|: *:]] [i] right , -1 !.]		`cyl	def	\ cylinder;
[swap 2 list |:]				`rpair 	def	\ a b -> [b a];
[swap dup #: !: [rpair] dip [gen] right]	`ca 	def	\ 15 start 30 rule ca;
[_ 3 #. 2 swap sv @]				`cell 	def	\ x y z -> n;
[[1 unlist] dip swap sheet cell] 		`gen 	def	\ can substitute cyl for sheet;
[stack flatten " *" of sysout;]			`disp	def	\ display;

30 start 25 [90 rule ca] Do disp				\ 30 wide, 25 gens, rule 90;