A skier traveling downhill through mostly untouched snow.
Nobody is traveling
If a skier is traveling then Nobody is not traveling.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & through(e1,x4) & n_snow(x4) & a_untouched(s1) & Theme(s1,x4) & r_mostly(x4) & Theme(e1,x3) & Actor(e1,x2) & v_travel(e1) & n_downhill(x3) & (x1 = x2) & n_skier(x1))
-exists e1 x1.(Actor(e1,x1) & v_travel(e1) & n_person(x1))