A dirt biker showing his biking skills on an off road course in the woods.
A dirt biker is riding outside.
If a biker is riding then he is biking
(x)
exists e1 s1 x1 x2.(a_outside(s1) & Manner(e1,s1) & Actor(e1,x1) & v_ride(e1) & n_biker(x1) & of(x1,x2) & n_dirt(x2))