proposition: Theorem lognat_prod_sum : forall(a : nat)(pf1 : (a <> 0))(pf2: (2 * a) <> 0), (S (lognat pf1)) = (lognat pf2).
proof: Proof. intros. unfold lognat in *. rewrite (factor_double_conv pf1 pf2). eapply log2_prod_sum. Qed.
imports: ZArith micromega.Lia