Definition BDDvar_make (cfg : BDDconfig) (x : BDDvar) :=
BDDmake cfg x BDDzero BDDone.

Lemma BDDvar_make_preserves_bool_fun :
forall (cfg : BDDconfig) (x : BDDvar),
BDDconfig_OK cfg ->
forall node : ad,
config_node_OK cfg node ->
bool_fun_eq (bool_fun_of_BDD (fst (BDDvar_make cfg x)) node)
(bool_fun_of_BDD cfg node).