proposition: Lemma int_to_nat_le_l x y : 0 ≤ x → x ≤ y → f (int_to_nat Z N x) ≤ y.
proof: Proof. intros. now rewrite int_to_nat_of_nonneg. 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