cellular automaton schoen ;
          /* Activation-Inhibition CA */
type celltype = boolean;
const dimension = 2;
      distance = 1;
group neighbors2 = {*[0,1],*[0,-1],*[1,0],*[-1,0]};
group neighbors3 = {*[1,1],*[-1,1],*[1,-1],*[-1,-1]};

initial 
    [true] ~ x = lx/2 and ( y = ly/2 or y = ly/2+1 or y = ly/2-1);
    [true] ~ y = ly/2 and ( x = lx/2+1 or x = lx/2-1 );
    
    [true] ~ prob(0.5) and option = 1;
    [false] ~ true;

color   [255,0,0]   ~ *[0,0];
 
var   c: celltype;

rule begin
   if (prob(0.1)) then 
   	*[0,0] := num ( c in neighbors2 : c ) >= 2 and 
   		num (c in neighbors3 :c ) <= 2;
end;