A dirt bike rider is midair while on a trail.
A dirt bike rider is resting on rock.
He is either midair on a trail or resting on a rock.
exists s1 x1 x2 x3 x4.(on(s1,x4) & n_trail(x4) & r_while(s1) & Theme(s1,x1) & a_midair(s1) & n_rider(x1) & of(x1,x3) & n_bike(x3) & of(x1,x2) & n_dirt(x2))
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_rock(x4) & Actor(e1,x1) & v_rest(e1) & n_rider(x1) & of(x1,x3) & n_bike(x3) & of(x1,x2) & n_dirt(x2))