A man stands on the back of a trash truck.
A person is standing on a vehicle
A man is a person a trash truck is a vehicle and back of a trash truck is part of the vehicle hence the person is standing on a vehicle.
exists e1 x1 x2 x3 x4.(n_back(x2) & on(e1,x2) & of(x2,x3) & n_truck(x3) & of(x3,x4) & n_trash(x4) & Actor(e1,x1) & v_stand(e1) & n_man(x1))
exists e1 x1 x2.(on(e1,x2) & n_vehicle(x2) & Actor(e1,x1) & v_stand(e1) & n_person(x1))