A man stands astride a bike on a rocky trail by a lake.
The man is biking in the outdoors.
One has to be astride a bike to be biking.  A lake is found outside in the open, hence the man is outdoors.
exists e1 s1 x1 x2 x3 x4.(astride(e1,x2) & by(x2,x4) & n_lake(x4) & on(x2,x3) & n_trail(x3) & a_rocky(s1) & Theme(s1,x3) & n_bike(x2) & Actor(e1,x1) & v_stand(e1) & n_man(x1))
exists e1 x1 x2.(n_outdoors(x2) & n_man(x1) & in(e1,x2) & Actor(e1,x1) & v_bike(e1))