-module(guards). -export([old_enough/1, right_age/1, wrong_age/1]). old_enough(X) when X >= 16 -> true; old_enough(_) -> false. right_age(X) when X >= 16, X =< 104 -> true; right_age(_) -> false. wrong_age(X) when X < 16; X > 104 -> true; wrong_age(_) -> false.