Definition BDDor_memo_put (cfg : BDDconfig) (node1 node2 node' : ad) :=
  match cfg with
  | (bs, (share, (fl, (cnt, (negm, (orm, um)))))) =>
      (bs,
      (share, (fl, (cnt, (negm, (MapPut2 _ orm node1 node2 node', um))))))
  end.

Lemma BDDorm_put_nodes_preserved : forall (cfg : BDDconfig) (node1 node2 node' : ad), nodes_preserved cfg (BDDor_memo_put cfg node1 node2 node').