The dirt bike rider is deep in the sand.
A bicyclist fell into the sand after messing up a trick.
Not all bike rider is deep in the sand because of messing up a trick.
exists s1 x1 x2 x3 x4.(n_sand(x4) & n_rider(x1) & of(x1,x3) & n_bike(x3) & of(x1,x2) & n_dirt(x2) & in(s1,x4) & Theme(s1,x1) & a_deep(s1))
exists e2 e1 s1 x1 x2 x3.(n_sand(x2) & after(e1,e2) & a_up(s1) & Manner(e2,s1) & Theme(e2,x3) & Actor(e2,x1) & v_mess(e2) & n_trick(x3) & into(e1,x2) & Actor(e1,x1) & v_fall(e1) & n_bicyclist(x1))