Bikers race through a forest.
Bikers are repairing their bikes in a field.
A forest is not a field. Also, people repairing their bikes cannot simultaneously race.
exists x1 x2 x3.(a_topic(x1) & through(x1,x3) & n_forest(x3) & n_race(x1) & of(x1,x2) & n_biker(x2))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_repair(e1) & in(x2,x3) & n_field(x3) & n_bike(x2) & of(x2,x1) & n_thing(x1) & n_biker(x1))