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 BDDzero_preserved : forall bs bs' : BDDstate, BDDstate_OK bs -> node_preserved_bs bs bs' BDDzero.