A black dog frolics in the snow.
Dog playing in snow
To frolic in the snow is the same thing as playing.  So a dog frolicking in the snow is a dog playing in the snow.
exists s1 x1 x2 x3.(n_snow(x3) & a_topic(x1) & in(x1,x3) & n_frolic(x1) & of(x1,x2) & n_dog(x2) & a_black(s1) & Theme(s1,x1))
exists x1 x2 x3.(a_topic(x1) & in(x1,x3) & n_snow(x3) & n_playing(x1) & (x1 = x2) & ne_nam_dog(x2))