Four people in the subway are having fun.
Four friends are laughing on a subway
You can't look at people and know if they are friends.
exists e1 x1 x2 x3.(n_subway(x2) & Theme(e1,x3) & Actor(e1,x1) & v_have(e1) & n_fun(x3) & in(x1,x2) & n_people(x1) & card_eq_4(x1))
exists e1 x1 x2.(on(e1,x2) & n_subway(x2) & Actor(e1,x1) & v_laugh(e1) & n_friend(x1) & card_eq_4(x1))