proposition: Lemma mult_pow2_bound: forall a b x y, x < pow2 a -> y < pow2 b -> x * y < pow2 (a + b).
proof: Proof. intros. rewrite pow2_add_mul. apply Nat.mul_lt_mono_nonneg; lia. Qed.
imports: Coq.Classes.Morphisms Coq.Classes.Morphisms_Prop Coq.Bool.Bool Coq.Arith.Arith Coq.micromega.Lia Coq.NArith.NArith Coq.ZArith.ZArith bbv.N_Z_nat_conversions bbv.Nomega