people are skiing down a snow covered hill
People are outside during winter.
a snow covered hill indicates it is outside during winter.
exists e2 e1 s1 x1 x2 x3.(a_down(s1) & Manner(e2,s1) & Theme(e2,x2) & Actor(e2,x1) & v_ski(e2) & n_hill(x2) & Theme(e1,x2) & v_cover(e1) & of(x2,x3) & n_snow(x3) & n_people(x1))
exists s1 x1 x2.(during(s1,x2) & n_winter(x2) & Theme(s1,x1) & a_outside(s1) & n_people(x1))