Two healthy horses play in a field.
Some mares are frolicking in tall grass.
Not every field contains tall grass.
exists e1 s1 x1 x2.(in(e1,x2) & n_field(x2) & Actor(e1,x1) & v_play(e1) & n_horse(x1) & a_healthy(s1) & Theme(s1,x1) & card_eq_2(x1))
exists e1 s1 x1 x2.(in(e1,x2) & n_grass(x2) & a_tall(s1) & Theme(s1,x2) & Actor(e1,x1) & v_frolic(e1) & n_mare(x1))