A rider on a dirt bike races through a forest.
A rider on a bike races through the forest.
Through the forest and through a forest share the same meaning.
exists x1 x2 x3 x4 x5.(a_topic(x1) & through(x1,x5) & n_forest(x5) & on(x1,x2) & n_race(x2) & of(x2,x4) & n_bike(x4) & of(x2,x3) & n_dirt(x3) & n_rider(x1))
exists x1 x2 x3 x4.(n_forest(x4) & a_topic(x1) & through(x1,x4) & on(x1,x2) & n_race(x2) & of(x2,x3) & n_bike(x3) & n_rider(x1))