A dog swims in a pool.
A puppy is swiming.
The dog isn't necessarily young so may not be a puppy.
exists e1 x1 x2.(in(e1,x2) & n_pool(x2) & Actor(e1,x1) & v_swim(e1) & n_dog(x1))
exists e1 x1.(Actor(e1,x1) & v_swime(e1) & n_puppy(x1))