proposition: Lemma int_abs_1 : int_abs Z N 1 = 1.
proof: Proof. apply (injective f). rewrite preserves_1. apply int_abs_nonneg; solve_propholds. 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