Two adults stand up on a bus and watch out the front window.
Everybody is sitting down on the bus.
Everybody can not be sitting if two are standing up.
exists e1 e2 s1 s2 x1 x2 x3 x4 x5.(n_window(x4) & of(x4,x5) & n_front(x5) & a_out(s2) & Manner(e2,s2) & Theme(e2,x4) & Actor(e2,x3) & v_watch(e2) & n_adult(x3) & card_eq_2(x3) & on(e1,x2) & n_bus(x2) & a_up(s1) & Manner(e1,s1) & Actor(e1,x1) & v_stand(e1) & n_adult(x1) & card_eq_2(x1))
exists x2.(n_bus(x2) & all x1.(n_person(x1) -> exists e1 s1.(on(e1,x2) & a_down(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1))))