proposition: Lemma int_to_nat_cancel_l x n : x = f n → int_to_nat Z N x = n.
proof: Proof. intros E. now rewrite E, int_to_nat_nat. 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