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 used_nodes_preserved_trans : forall (cfg1 cfg2 cfg3 : BDDconfig) (ul : list ad), BDDconfig_OK cfg1 -> used_nodes_preserved cfg1 cfg2 ul -> used_nodes_preserved cfg2 cfg3 ul -> used_nodes_preserved cfg1 cfg3 ul.