Children are running on a grass field.
Children running down a city street.
A grass field cannot be a city street.
exists e1 x1 x2 x3.(on(e1,x2) & n_field(x2) & of(x2,x3) & n_grass(x3) & Actor(e1,x1) & v_run(e1) & n_child(x1))
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & a_down(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x2) & v_run(e1) & n_street(x3) & of(x3,x4) & n_city(x4) & (x1 = x2) & n_child(x1))