Dog walking on the beach by the ocean.
A dog being walked by its owner.
Just because a dog is walking on a beach does not mean it is being walked by its owner.
exists x1 x2 x3 x4.(n_ocean(x4) & n_beach(x3) & a_topic(x1) & on(x1,x3) & by(x3,x4) & n_walking(x1) & (x1 = x2) & ne_nam_dog(x2))
exists e1 x1 x2 x3.(by(e1,x3) & n_owner(x3) & of(x3,x1) & n_thing(x1) & Actor(e1,x1) & v_walk(e1) & n_being(x1) & of(x1,x2) & n_dog(x2))