A man is giving a presentation.
A man is standing in the front of a room.
Not all persons giving a presentation is standing in the front of a room.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_give(e1) & n_presentation(x2) & n_man(x1))
exists e1 x1 x2 x3.(n_front(x2) & in(e1,x2) & of(x2,x3) & n_room(x3) & Actor(e1,x1) & v_stand(e1) & n_man(x1))