A janitor stands on a moving walkway whilst cleaning in an airport.
a janitor cleans the airport
cleaning in an airport is a rephrasing of cleans the airport
exists e1 e2 x1 x2 x3 x4 x5.(on(e1,x2) & in(x2,x5) & n_airport(x5) & n_cleaning(x2) & of(x2,x4) & n_whilst(x4) & of(x2,x3) & n_walkway(x3) & Actor(e2,x2) & v_move(e2) & Actor(e1,x1) & v_stand(e1) & n_janitor(x1))
exists e1 x1 x2.(n_airport(x2) & Theme(e1,x2) & Actor(e1,x1) & v_clean(e1) & n_janitor(x1))