A man is giving a presentation in front of a lot of people.
the man is obama
Not all male presenters are Obama.
exists e1 x1 x2 x3 x4 x5.(Theme(e1,x2) & Actor(e1,x1) & v_give(e1) & in(x2,x3) & of(x3,x4) & of(x4,x5) & n_people(x5) & n_lot(x4) & n_front(x3) & n_presentation(x2) & n_man(x1))
exists p1 x1.(n_man(x1) & exists x2.((x1 = x2) & n_obama(x2)))