A person skis down a steep snowy hill.
a person rode the ski lift up the mountain
Not all people ride the ski lift after skiing down a hill.
exists e1 s1 s2 s3 x1 x2.(a_down(s3) & Manner(e1,s3) & Theme(e1,x2) & Actor(e1,x1) & v_ski(e1) & n_hill(x2) & a_snowy(s2) & Theme(s2,x2) & a_steep(s1) & Theme(s1,x2) & n_person(x1))
exists e1 x1 x2 x3 x4.(n_mountain(x4) & n_lift(x2) & of(x2,x3) & n_ski(x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & up(x2,x4) & n_person(x1))