A child hangs upside down on a ladder while another child swings on a rope.
A child fell off a ladder.
The child either hangs upside down or fell off, one cannot do both at the same time.
exists e1 p1 x1 x2 x3 x4 x5 x6.(on(e1,x6) & n_rope(x6) & while(e1,x4) & n_swing(x4) & of(x4,x5) & n_child(x5) & -(x4 = x3) & n_swing(x3) & of(x3,x1) & n_child(x1) & n_child(x1) & on(e1,x2) & n_ladder(x2) & exists s1.(r_upside(s1) & Theme(s1,x1) & a_down(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_hang(e1))
exists e1 s1 x1 x2.(a_off(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_fall(e1) & n_ladder(x2) & n_child(x1))