proposition: Lemma between_to_ring n : -f n ≤ f n.
proof: Proof. apply between_nonneg. now apply to_semiring_nonneg. Qed.
imports: Coq.setoid_ring.Ring MathClasses.interfaces.abstract_algebra MathClasses.interfaces.naturals MathClasses.interfaces.orders MathClasses.orders.rings MathClasses.orders.nat_int