A man speaking at a conference.
A man is holding a microphone.
Not all men are holding a microphone.
exists x1 x2 x3.(a_topic(x1) & at(x1,x3) & n_conference(x3) & n_speaking(x1) & of(x1,x2) & n_man(x2))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_hold(e1) & n_microphone(x2) & n_man(x1))