A snowboarder grinding up a homemade ramp.
There is no snow on the ground.
The snowboarder cannot snowboard if there is no snow.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & a_up(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x2) & v_grind(e1) & n_ramp(x3) & of(x3,x4) & n_homemade(x4) & (x1 = x2) & n_snowboarder(x1))
exists p1 x1 x3.(n_ground(x3) & -exists x2.((x1 = x2) & on(x2,x3) & n_snow(x2)))