(* Share universes *)
  Implicit Types A B C : Type.Class Proper (R : crelation A) (m : A) :=
    proper_prf : R m m.Class Proper (R : crelation A) (m : A) :=
    proper_prf : R m m.(** Every element in the carrier of a reflexive relation is a morphism
   for this relation.  We use a proxy class for this case which is used
   internally to discharge reflexivity constraints.  The [Reflexive]
   instance will almost always be used, but it won't apply in general to
   any kind of [Proper (A -> B) _ _] goal, making proof-search much
   slower. A cleaner solution would be to be able to set different
   priorities in different hint bases and select a particular hint
   database for resolution of a type class constraint. *)

  Class ProperProxy (R : crelation A) (m : A) :=
    proper_proxy : R m m.(** Every element in the carrier of a reflexive relation is a morphism
   for this relation.  We use a proxy class for this case which is used
   internally to discharge reflexivity constraints.  The [Reflexive]
   instance will almost always be used, but it won't apply in general to
   any kind of [Proper (A -> B) _ _] goal, making proof-search much
   slower. A cleaner solution would be to be able to set different
   priorities in different hint bases and select a particular hint
   database for resolution of a type class constraint. *)

  Class ProperProxy (R : crelation A) (m : A) :=
    proper_proxy : R m m.

Lemma eq_proper_proxy (x : A) : ProperProxy (@eq A) x.