A snowboarder leaves a trail of snow on the mountain.
The snowboarder fell down the mountain
Just because a snowboarder leaves a trail of snow on the mountain doesn't imply the snowboarder fell down.
exists e1 x1 x2 x3 x4.(n_mountain(x4) & Theme(e1,x2) & Actor(e1,x1) & v_leave(e1) & on(x2,x4) & of(x2,x3) & n_snow(x3) & n_trail(x2) & n_snowboarder(x1))
exists e1 s1 x1 x2.(n_mountain(x2) & n_snowboarder(x1) & a_down(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_fall(e1))