A man on stage with a microphone in front of an audience.
the man is ina  barrel and about to go down the falls
One cannot be on stage and in a barrel about to go down the falls at the same time.
exists x1 x2 x3 x4 x5.(a_topic(x1) & on(x1,x2) & with(x2,x3) & in(x3,x4) & of(x4,x5) & n_audience(x5) & n_front(x4) & n_microphone(x3) & n_stage(x2) & n_man(x1))
exists e1 p1 p2 s1 x1 x2 x3.(n_man(x1) & while(e1,s1) & Actor(e1,x3) & v_fall(e1) & n_the(x3) & Topic(s1,p2) & Actor(s1,x2) & a_about(s1) & exists e2 s3.(a_down(s3) & Manner(e2,s3) & Actor(e2,x2) & v_go(e2)) & n_thing(x2) & exists s2 x4.((x1 = x4) & n_barrel(x4) & a_ina(s2) & Theme(s2,x4)))