A race car driver.
A pilot.
A race car driver and a pilot are two very different people.
exists x1 x2 x3.(a_topic(x1) & n_driver(x1) & of(x1,x3) & n_car(x3) & of(x1,x2) & n_race(x2))
exists x1.(a_topic(x1) & n_pilot(x1))