A dirt biker goes down a dirt hill.
A man on a bicycle is riding on land.
The dirt is land, and a biker is the description of someone who rides bikes.
exists e1 s1 x1 x2 x3 x4.(a_down(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x1) & v_go(e1) & n_hill(x3) & of(x3,x4) & n_dirt(x4) & n_biker(x1) & of(x1,x2) & n_dirt(x2))
exists e1 x1 x2 x3.(on(e1,x3) & n_land(x3) & Actor(e1,x1) & v_ride(e1) & on(x1,x2) & n_bicycle(x2) & n_man(x1))