a man on a race bike
A man riding a vehicle.
A race bike is a type of vehicle.
exists x1 x2 x3.(a_topic(x1) & on(x1,x2) & n_bike(x2) & of(x2,x3) & n_race(x3) & n_man(x1))
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_vehicle(x3) & (x1 = x2) & n_man(x1))