A white dog and a black dog running side by side on the grass while onlookers watch.
Two dogs run side by side on some grass.
He refers to a white dog and a black dog which implies two dogs.
exists e1 p1 s1 s2 s3 x1 x2 x3 x4 x5 x6.(n_grass(x6) & a_topic(s1) & subset_of(x2,s1) & exists e2 x7.(Actor(e2,x7) & v_watch(e2) & n_onlooker(x7)) & while(e1,p1) & on(e1,x6) & by(e1,x5) & n_side(x5) & Theme(e1,x4) & Actor(e1,x3) & v_run(e1) & n_side(x4) & (x2 = x3) & n_dog(x2) & a_black(s3) & Theme(s3,x2) & subset_of(x1,s1) & n_dog(x1) & a_white(s2) & Theme(s2,x1))
exists e1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_run(e1) & by(x2,x3) & on(x3,x4) & n_grass(x4) & n_side(x3) & n_side(x2) & n_dog(x1) & card_eq_2(x1))