true.
:-false.
neg_fly:-ap(1).
fly:-winged,not neg_fly.
ap(1):-ok(1),penguin,not fly.
ap(2):-ok(2),bird,not neg_winged.
ok(X):-name(X),oko(X,1),oko(X,2).
penguin:-true.
bl(1):-ok(1),not penguin.
bl(1):-ok(1),fly.
bl(2):-ok(2),not bird.
bl(2):-ok(2),neg_winged.
winged:-ap(2).
bird:-penguin.
prec(2,1):-true.
neg_prec(Y,X):-name(X),name(Y),prec(X,Y).
prec(X,Z):-name(X),name(Z),name(Y),prec(X,Y),prec(Y,Z).
oko(X,Y):-name(X),name(Y),not prec(X,Y).
oko(X,Y):-name(X),name(Y),prec(X,Y),ap(Y).
oko(X,Y):-name(X),name(Y),prec(X,Y),bl(Y).
false:-fly,neg_fly.
false:-penguin,neg_penguin.
false:-winged,neg_winged.
false:-bird,neg_bird.
false:-name(X),name(Y),prec(X,Y),neg_prec(X,Y).
name(2).
name(1).