A bellhop is pushing a cart.
A person is pushing something
In a both sentence,a person is pushing.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_push(e1) & n_cart(x2) & n_bellhop(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_push(e1) & n_thing(x2) & n_person(x1))