dogs playing
The dog are playing together.
dogs playing already explains dogs playing together
exists e1 x1 x2.(a_topic(x1) & Actor(e1,x2) & v_play(e1) & (x1 = x2) & n_dog(x1))
exists e1 s1 x1.(n_dog(x1) & a_together(s1) & Manner(e1,s1) & Actor(e1,x1) & v_play(e1))