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

Lemma CG_add_edge_1 :
forall x0 y0 : ad,
CG_edge cg2 x0 y0 =
(if N.eqb x x0 && N.eqb y y0
then Ddmin (Some d) (CG_edge cg1 x0 y0)
else CG_edge cg1 x0 y0).