Through the truck's rear window you can see the back of the seats as well as the rear view mirror.
There is no one inside the truck.
Just because you can see the back doesn't mean no one is inside
exists e1 p1 s1 x1 x2 x3 x5 x6 x7.(n_window(x2) & of(x2,x3) & n_rear(x3) & of(x2,x1) & n_truck(x1) & n_view(x7) & a_rear(s1) & Theme(s1,x7) & n_seat(x6) & n_back(x5) & n_person(x1) & through(e1,x2) & exists e2 x4 x8.(Theme(e2,x4) & Actor(e2,x1) & v_see(e2) & subset_of(x7,x4) & Time(x7,x8) & n_mirror(x8) & subset_of(x5,x4) & of(x5,x6)) & Topic(e1,p1) & Actor(e1,x1) & v_can(e1))
exists p1 x1 x3.(n_truck(x3) & -exists x2.((x1 = x2) & inside(x2,x3) & n_one(x2)))