Section CGAdd.
Variable cg1 : CGraph1.
Variable x y : ad.
Variable d : D.
Definition cg2 := CG_add cg1 x y d.

Lemma CG_add_4_4 :
forall (l : list ad) (last : ad) (d0 : D),
CG_path cg2 last d0 l -> ad_in_list x l = false -> CG_path cg1 last d0 l.