Definition BDDor :=
  BDDor_1 gc cfg ul node1 node2
    (S
       (max (nat_of_N (node_height cfg node1))
          (nat_of_N (node_height cfg node2)))).

Lemma BDDor_is_or : bool_fun_eq (bool_fun_of_BDD (fst BDDor) (snd BDDor)) (bool_fun_or (bool_fun_of_BDD cfg node1) (bool_fun_of_BDD cfg node2)).