A man and women are on a bus.
A man and woman talking to each other on a bus.
A man and a woman on a bus don't have to talk to each other.
exists p1 x1 x2 x3.(exists x4.(on(x1,x4) & n_bus(x4)) & subset_of(x3,x1) & n_woman(x3) & subset_of(x2,x1) & n_man(x2))
exists e1 s1 x1 x2 x3 x4.(a_topic(s1) & on(e1,x4) & n_bus(x4) & all x5.(n_other(x5) -> to(e1,x5)) & Actor(e1,x3) & v_talk(e1) & (s1 = x3) & n_woman(x2) & n_man(x1) & subset_of(x2,s1) & subset_of(x1,s1))