fact: Definition bool_fun_and (bf1 bf2 : bool_fun) : bool_fun := fun vb : var_binding => bf1 vb && bf2 vb.
imports: Bool Sumbool Arith ZArith NArith Nnat Ndec Ndigits IntMap(Allmaps) Wf_nat BDDvar_ad_nat bdd1 bdd2 bdd3 bdd4 bdd5_1 bdd5_2 bdd6 bdd7 BDDdummy_lemma_2 BDDdummy_lemma_3 BDDdummy_lemma_4 bdd8 bdd9