Section Components.
Variable cfg : BDDconfig.
Hypothesis cfg_OK : BDDconfig_OK cfg.
Definition bs_of_cfg := fst cfg.
Definition share_of_cfg := fst (snd cfg).
Definition fl_of_cfg := fst (snd (snd cfg)).
Definition cnt_of_cfg := fst (snd (snd (snd cfg))).
Definition negm_of_cfg := fst (snd (snd (snd (snd cfg)))).
Definition orm_of_cfg := fst (snd (snd (snd (snd (snd cfg))))).
Definition um_of_cfg := snd (snd (snd (snd (snd (snd cfg))))).

Lemma nodes_reachable_lemma_1 :
forall (bs : BDDstate) (node node' : ad),
nodes_reachable bs node node' ->
node = node' \/
(exists x : BDDvar,
(exists l : ad,
(exists r : ad,
MapGet _ bs node = Some (x, (l, r)) /\
(nodes_reachable bs l node' \/ nodes_reachable bs r node')))).