Definition BDDneg_memo_put (cfg : BDDconfig) (node node' : ad) :=
  match cfg with
  | (bs, (share, (fl, (cnt, (negm, z))))) =>
      (bs, (share, (fl, (cnt, (MapPut _ negm node node', z)))))
  end.

Lemma BDDnegm_put_OK : forall (cfg : BDDconfig) (node node' : ad), BDDconfig_OK cfg -> config_node_OK cfg node -> config_node_OK cfg node' -> Neqb (node_height cfg node') (node_height cfg node) = true -> bool_fun_eq (bool_fun_of_BDD cfg node') (bool_fun_neg (bool_fun_of_BDD cfg node)) -> BDDconfig_OK (BDDneg_memo_put cfg node node').