proposition: Lemma int_to_nat_le_cancel_l x n : 0 ≤ x → x ≤ f n → int_to_nat Z N x ≤ n.
proof: Proof. intros. now apply (order_reflecting f), int_to_nat_le_l. Qed.
imports: Coq.setoid_ring.Ring MathClasses.interfaces.naturals MathClasses.interfaces.abstract_algebra MathClasses.interfaces.orders MathClasses.orders.nat_int MathClasses.theory.integers MathClasses.theory.rings MathClasses.orders.rings