A person runs in a competition in front of onlookers.
A person is singing for an audience.
Person who is singing for an audience can not runs in a competition at the same time.
exists e1 x1 x2 x3 x4.(in(e1,x2) & in(x2,x3) & of(x3,x4) & n_onlooker(x4) & n_front(x3) & n_competition(x2) & Actor(e1,x1) & v_run(e1) & n_person(x1))
exists e1 x1 x2.(for(e1,x2) & n_audience(x2) & Actor(e1,x1) & v_sing(e1) & n_person(x1))