Three dogs are playing.
A group of three dogs are playing.
group of dogs are playing can also  be said ass three dogs are playing
exists e1 x1.(Actor(e1,x1) & v_play(e1) & n_dog(x1) & card_eq_3(x1))
exists e1 x1 x2.(Actor(e1,x1) & v_play(e1) & of(x1,x2) & n_dog(x2) & card_eq_3(x2) & n_group(x1))