[8 2 # swap vs reverse]                       			`rule    def 	\ 30 rule;
[dup 2 * &: 1 concat !]                       			`start   def 	\ 3 start -> 1 1 1 0 1 1 1;
[2 [0 concat reverse] do]                     			`sheet   def 	\ sheet;
[dup [first [reverse first]] [i] right concat -1 swap !]	`cyl	 def 	\ cylinder;
[swap 2 list reverse]                        			`rpair   def 	\ a b -> [b a];
[swap dup size !: [rpair] dip [gen] right]    			`ca      def 	\ 15 start 30 rule ca;
[swap drop 3 swap # 2 swap sv at]             			`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;