Two large brown dogs are playing in the grass.
two dogs play while a third looks on
Two dogs playing in the grass does not imply a third dog is there.
exists e1 s1 s2 x1 x2.(n_grass(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_dog(x1) & a_brown(s2) & Theme(s2,x1) & a_large(s1) & Theme(s1,x1) & card_eq_2(x1))
exists e1 s1 s2 x1 x2.(a_on(s2) & Manner(e1,s2) & while(e1,x2) & n_look(x2) & a_third(s1) & Theme(s1,x2) & Actor(e1,x1) & v_play(e1) & n_dog(x1) & card_eq_2(x1))