Three children are standing in front of a billboard advertisement.
there is a clown on the billboard
Children standing in front of a billboard does not prove there is a clown on the billboard.
exists e1 x1 x2 x3 x4.(in(e1,x2) & of(x2,x3) & n_advertisement(x3) & of(x3,x4) & n_billboard(x4) & n_front(x2) & Actor(e1,x1) & v_stand(e1) & n_child(x1) & card_eq_3(x1))
exists p1 x1 x3.(n_billboard(x3) & exists x2.((x1 = x2) & on(x2,x3) & n_clown(x2)))