A snowboarder crashes into another.
A snowboarder crashes.
Snowboarders sometimes crashes into another.
exists e1 x1 x2.(into(e1,x2) & n_thing(x2) & Actor(e1,x1) & v_crash(e1) & n_snowboarder(x1))
exists x1 x2.(a_topic(x1) & n_crash(x1) & of(x1,x2) & n_snowboarder(x2))