A boy climbs rocks.
A boy is playing outside on rocks.
A boy who climbs rocks is playing outside.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_climb(e1) & n_rock(x2) & n_boy(x1))
exists e1 x1 x2 x3.(on(e1,x3) & n_rock(x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_outside(x2) & n_boy(x1))