Older gentleman smoking while walking by a painting of an old man.
Old men are riding horses.
One can either be walking themselves or riding a horse.
(x)
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_horse(x2) & n_man(x1) & a_old(s1) & Theme(s1,x1))