Bikers race through a forest.
Bikers crash in the forest.
Racing does not mean a crash.
exists x1 x2 x3.(a_topic(x1) & through(x1,x3) & n_forest(x3) & n_race(x1) & of(x1,x2) & n_biker(x2))
exists x1 x2 x3.(n_forest(x3) & a_topic(x1) & in(x1,x3) & n_crash(x1) & of(x1,x2) & n_biker(x2))