x : (integers_to_ring Z R ∘ f^-1) x = h x. Proof. transitivity ((h ∘ (f ∘ f^-1)) x). - symmetry. apply (to_ring_unique (h ∘ f)). - unfold Compose. apply ap. apply eisretr. Qed.
Require Import Require Import Import NatPair.Instances.