A bicyclist racing in a bike race.
A biker in a race.
biker is a bicyclist
exists x1 x2 x3 x4.(a_topic(x1) & in(x1,x3) & n_race(x3) & of(x3,x4) & n_bike(x4) & n_racing(x1) & of(x1,x2) & n_bicyclist(x2))
exists x1 x2.(a_topic(x1) & in(x1,x2) & n_race(x2) & n_biker(x1))