A dog looks behind itself.
A dog is looking.
If someone looks they are looking
exists e1 x1.(behind(e1,x1) & n_thing(x1) & Actor(e1,x1) & v_look(e1) & n_dog(x1))
exists e1 x1.(Actor(e1,x1) & v_look(e1) & n_dog(x1))