A man cooking outside on a grill.
Man cooking hamburgers on a grill.
Just because a man is cooking on an outside grill doesn't imply he is cooking hamburgers.
exists x1 x2 x3 x4.(a_topic(x1) & on(x3,x4) & n_grill(x4) & outside(x1,x3) & n_thing(x3) & n_cooking(x1) & of(x1,x2) & n_man(x2))
exists x1 x2 x3 x4.(a_topic(x1) & on(x1,x4) & n_grill(x4) & n_hamburger(x1) & of(x1,x3) & n_cooking(x3) & of(x1,x2) & n_man(x2))