Section BDDquant.
Variable gc : BDDconfig -> list ad -> BDDconfig.
Hypothesis gc_is_OK : gc_OK gc.
Section BDDuniv_results.
Variable cfg : BDDconfig.
Variable ul : list ad.
Variable y : BDDvar.
Variable node : ad.
Hypothesis cfg_OK : BDDconfig_OK cfg.
Hypothesis ul_OK : used_list_OK cfg ul.
Hypothesis used : used_node' cfg ul node.
Definition BDDuniv :=
BDDuniv_1 gc cfg ul node y (S (nat_of_N (node_height cfg node))).
Let lt_1 :
nat_of_N (node_height cfg node) < S (nat_of_N (node_height cfg node)).

Lemma BDDuniv_used_nodes_preserved :
used_nodes_preserved cfg (fst BDDuniv) ul.