A child plays on the dirt.
a child plays with dirt
A child who is playing with dirt must be located somewhere on the dirt.
exists e1 x1 x2.(n_dirt(x2) & on(e1,x2) & Actor(e1,x1) & v_play(e1) & n_child(x1))
exists e1 x1 x2.(with(e1,x2) & n_dirt(x2) & Actor(e1,x1) & v_play(e1) & n_child(x1))