A dirt biker showing his biking skills on an off road course in the woods.
A man is dirt biking on the beach.
The biker is either on the beach or on an in the woods.
(x)
exists p1 x1 x3.(n_beach(x3) & exists s1 x2.((x1 = x2) & on(x2,x3) & n_biking(x2) & a_dirt(s1) & Theme(s1,x2)) & n_man(x1))