A jockey in blue on a race horse trails behind the jockey in orange.
A jockey is on a horse.
jockey on a race horse trails implies that he is on a horse.
exists x1 x2 x3 x4 x5 x6.(a_topic(x1) & in(x1,x2) & on(x2,x3) & behind(x3,x1) & in(x1,x6) & n_orange(x6) & n_jockey(x1) & n_jockey(x1) & n_trail(x3) & of(x3,x5) & n_horse(x5) & of(x3,x4) & n_race(x4) & n_blue(x2))
exists p1 x1.(exists x2.(on(x1,x2) & n_horse(x2)) & n_jockey(x1))