There are four people talking in the phone booths.
One person is talking to their mother.
It is not possible to tell who anyone is talking to, it is possible nobody is talking to their mother.
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.(to(e1,x2) & n_mother(x2) & of(x2,x1) & n_thing(x1) & Actor(e1,x1) & v_talk(e1) & n_person(x1) & card_eq_1(x1))