fact: Definition is_internal_node (cfg : BDDconfig) (node : ad) := exists x : BDDvar, (exists l : ad, (exists r : ad, MapGet _ (fst cfg) node = Some (x, (l, r)))).
imports: Bool Sumbool Arith ZArith NArith Nnat Ndec Ndigits IntMap(Allmaps) Wf_nat BDDvar_ad_nat bdd1