A dog swims in a pool.
A poodle is swimming.
Not every dog is a poodle.
exists e1 x1 x2.(in(e1,x2) & n_pool(x2) & Actor(e1,x1) & v_swim(e1) & n_dog(x1))
exists p1 x1.(exists x2.((x1 = x2) & n_swimming(x2)) & n_poodle(x1))