A dog in a field.
The dog is swimming in a pool.
Being in a field and swimming in a pool are very different things.
exists x1 x2.(a_topic(x1) & in(x1,x2) & n_field(x2) & n_dog(x1))
exists e1 x1 x2.(n_dog(x1) & in(e1,x2) & n_pool(x2) & Actor(e1,x1) & v_swim(e1))