people go up the escalator.
The people are on the escalator.
To go up the escalator, you must be on the escalator.
exists e1 s1 x1 x2.(n_escalator(x2) & a_up(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_go(e1) & n_people(x1))
exists p1 x1 x2.(n_escalator(x2) & n_people(x1) & on(x1,x2))