There are four people talking in the phone booths.
People using cell phones
Talking in phone booths does not imply cell phones.
exists p1 x1 x4 x5.(n_booth(x4) & of(x4,x5) & n_phone(x5) & exists e1 x2 x3.((x1 = x2) & in(e1,x4) & Actor(e1,x3) & v_talk(e1) & (x2 = x3) & n_people(x2) & card_eq_4(x2)))
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_use(e1) & n_phone(x3) & of(x3,x4) & n_cell(x4) & (x1 = x2) & n_people(x1))