A group of people are going down an escalator.
People are on an escalator
Going down an escalator implies on an escalator.
exists e1 s1 x1 x2 x3.(a_down(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x1) & v_go(e1) & n_escalator(x3) & of(x1,x2) & n_people(x2) & n_group(x1))
exists p1 x1.(exists x2.(on(x1,x2) & n_escalator(x2)) & n_people(x1))