/e.g. r-pentomino:
/ **
/**
/ *

\m f fixedsys
\m l fixedsys
			
Organism:176				
N:10					
G:0						
Run:"U..e::0;do[N;U:next U];G+:N"			
Run..c:`button				
Edit:"U..e~:"				
Edit..c:`button				

U:50 50#0				
U..k:"if[U..e;.[`U;_i;~:]]"		
U..f..d:"_ci[32,.k.Organism]@"				
U..e:0

next:{(x&2=k)|3=k:+/adj x}
adj:{(r'r@;r'l@;l'r@;l'l@;l';r';r:-1!;l:1!)@\:x}

.k..c:`form				
.k..l..d:"$.k.G"			
.k..a:(`N`Organism`Run`Edit;`U)	

`show$`.k;