Two horses walking threw the grass.
Two horses are grazing the grass outside.
Grazing indicates a pause to eat which is not possible if they are walking through.
exists e1 e2 x1 x2 x3.(n_grass(x3) & Theme(e2,x3) & Actor(e2,x1) & v_throw(e2) & Actor(e1,x2) & v_walk(e1) & (x1 = x2) & n_horse(x1) & card_eq_2(x1))
exists e1 x1 x2 x3.(n_outside(x2) & of(x2,x3) & n_grass(x3) & Theme(e1,x2) & Actor(e1,x1) & v_graze(e1) & n_horse(x1) & card_eq_2(x1))