A man in American flag shorts stands at the top of the stairs.
A North Korean supporter is riding in an elevator.
An elevator and stairs are different objects. Also, the person is either standing at the top of stairs, or riding an elevator - the tasks are non-compatible
exists e1 s1 x1 x2 x3 x4 x5.(n_stair(x5) & n_top(x4) & at(e1,x4) & of(x4,x5) & Theme(e1,x3) & Actor(e1,x1) & v_short(e1) & n_stand(x3) & in(x1,x2) & n_flag(x2) & a_american(s1) & Theme(s1,x2) & n_man(x1))
exists e1 s1 x1 x2.(in(e1,x2) & n_elevator(x2) & Actor(e1,x1) & v_ride(e1) & n_supporter(x1) & a_korean(s1) & Theme(s1,x1) & r_north(x1))