proposition: Lemma Zpower_equiv a b : a^^b = a^b.
proof: Proof. destruct b as [|p|p]; trivial. unfold Zpower_alt, Z.pow, Z.pow_pos. revert a. induction p; simpl; intros. - f_equal. rewrite Piter_mul_acc. + now rewrite Piter_op_square, IHp. + intros. symmetry; apply Z.mul_assoc. - rewrite Piter_mul_acc. + now rewrite Piter_op_square, IHp. + intros. symmetry; apply Z.mul_assoc. - now Z.nzsimpl. Qed.
imports: BinInt