A dog in the snow.
A dog is playing in the snow
Not all dogs in snow are playing.
exists x1 x2.(n_snow(x2) & a_topic(x1) & in(x1,x2) & n_dog(x1))
exists e1 x1 x2.(n_snow(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_dog(x1))