Two adults on cellphones downtown.
The two adults are on lunch.
The two adults on their cellphones does not mean that they are necessarily taking lunch.
exists x1 x2 x3.(a_topic(x1) & on(x1,x2) & n_downtown(x2) & of(x2,x3) & n_cellphone(x3) & n_adult(x1) & card_eq_2(x1))
exists p1 x1.(n_adult(x1) & card_eq_2(x1) & exists x2.(on(x1,x2) & n_lunch(x2)))