A horse race with numerous people on the horses in a grassy scene.
racers mount horses
If racers are mounting horses they cannot be already having a horse race.
exists s1 s2 x1 x2 x3 x4.(a_topic(x1) & with(x1,x3) & in(x3,x4) & n_scene(x4) & a_grassy(s2) & Theme(s2,x4) & on(x3,x2) & n_horse(x2) & n_horse(x2) & n_people(x3) & a_numerous(s1) & Theme(s1,x3) & n_race(x1) & of(x1,x2))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_mount(e1) & n_horse(x2) & n_racer(x1))