A shirtless man is riding a motorcycle.
The man is riding a Harley-Davidson
Not all motorcycles are Harley-Davidson
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_motorcycle(x2) & n_man(x1) & a_shirtless(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_harley-davidson(x2))