proposition: Lemma int_to_nat_1 : int_to_nat Z N 1 = 1.
proof: Proof. apply int_to_nat_cancel_l. now rewrite preserves_1. 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