The snowboarder is grinding on a silver rail in the nighttime snow.
The snowboarder is going down a hill in the daytime.
The snowboarder can't be grinding and going down a hill at the same time as well as it can't be nighttime and daytime at the same time.
exists e1 s1 x1 x2 x3 x4.(n_snow(x4) & a_nighttime(s1) & Theme(s1,x4) & n_snowboarder(x1) & on(e1,x2) & in(x2,x4) & n_rail(x2) & of(x2,x3) & n_silver(x3) & Actor(e1,x1) & v_grind(e1))
exists e1 s1 x1 x2 x3.(n_daytime(x3) & n_snowboarder(x1) & in(e1,x3) & a_down(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_go(e1) & n_hill(x2))