Lemma BDDneg_memo_OK_1_lemma_1_2' : forall (cfg : BDDconfig) (x : BDDvar) (l r node : ad) (n m : nat) (memo : BDDneg_memo), BDDconfig_OK cfg -> MapGet _ (fst cfg) node = Some (x, (l, r)) -> nat_of_N (var cfg node) < n -> n = S m -> BDDneg_memo_OK_2 (fst (BDDneg_2 (fst (BDDneg_2 cfg l m)) r m)) memo -> BDDneg_memo_OK_2 (fst (BDDneg_2 cfg node n)) (BDDneg_memo_put memo node (snd (BDDneg_2 cfg node n))).