A group of people running up a hill.
A group of people are walking downhill.
running up a hill is contradictory to walking downhill
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & of(x1,x2) & a_up(s1) & Manner(e1,s1) & Theme(e1,x4) & Actor(e1,x3) & v_run(e1) & n_hill(x4) & (x2 = x3) & n_people(x2) & n_group(x1))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_walk(e1) & n_downhill(x3) & of(x1,x2) & n_people(x2) & n_group(x1))