A person is riding an orange dirt bike is a desert setting.
A person racing in a event.
One can ride a dirt bike without being part of a specific event.
exists e1 p1 x1 x2 x3 x4 x5.(exists x6 x7.((x1 = x6) & n_setting(x6) & of(x6,x7) & n_desert(x7)) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_bike(x3) & of(x3,x5) & n_dirt(x5) & of(x3,x4) & n_orange(x4) & (x1 = x2) & n_person(x1))
exists x1 x2 x3.(a_topic(x1) & in(x1,x3) & n_event(x3) & Time(x1,x2) & n_racing(x2) & n_person(x1))