A boy with a ball playing on a playground.
A boy is eating lunch in the cafeteria.
If he is playing on a playground, he cannot be eating lunch in the cafeteria.
exists x1 x2 x3 x4.(a_topic(x1) & with(x1,x2) & on(x2,x4) & n_playground(x4) & n_playing(x2) & of(x2,x3) & n_ball(x3) & n_boy(x1))
exists e1 x1 x2 x3.(n_cafeteria(x3) & in(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & n_lunch(x2) & n_boy(x1))