A little boy climbing a rock wall.
The boy is on an airplane.
If a boy is climbing a rack wall, he cannot be on an airplane.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_climb(e1) & n_wall(x3) & of(x3,x4) & n_rock(x4) & (x1 = x2) & n_boy(x1) & a_little(s1) & Theme(s1,x1))
exists p1 x1.(n_boy(x1) & exists x2.(on(x1,x2) & n_airplane(x2)))