`{Funext} {A B : Ring} {f g : RingHomomorphism A B} : f == g <~> f = g. Proof. refine ((equiv_ap (issig_RingHomomorphism A B)^-1 _ _)^-1 oE _). refine (equiv_path_sigma_hprop _ _ oE _). apply equiv_path_forall. Defined.
Require Import WildCat. Require Import Spaces.Nat.Core Spaces.Nat.Arithmetic. Require Import Classes.interfaces.abstract_algebra. Require Import Algebra.Groups.Group Algebra.Groups.Subgroup. Require Import Modalities.ReflectiveSubuniverse.