End LRMorphismTheory.
Module ComRing.
Definition RingMixin R one mul mulA mulC mul1x mul_addl :=
let mulx1 := Monoid.mulC_id mulC mul1x in
let mul_addr := Monoid.mulC_dist mulC mul_addl in
@Ring.EtaMixin R one mul mulA mul1x mulx1 mul_addl mul_addr.
Section ClassDef.
Record class_of R :=
Class {base : Ring.class_of R; mixin : commutative (Ring.mul base)}.
Local Coercion base : class_of >-> Ring.class_of.
Structure type := Pack {sort; _ : class_of sort}.
Local Coercion sort : type >-> Sortclass.
Variable (T : Type) (cT : type).
Definition class := let: Pack _ c as cT' := cT return class_of cT' in c.
Definition clone c of phant_id class c := @Pack T c.
Let xT := let: Pack T _ := cT in T.
Notation xclass := (class : class_of xT).
Definition pack mul0 (m0 : @commutative T T mul0) :=
fun bT b & phant_id (Ring.class bT) b =>
fun    m & phant_id m0 m => Pack (@Class T b m).
Definition eqType := @Equality.Pack cT xclass.
Definition choiceType := @Choice.Pack cT xclass.
Definition zmodType := @Zmodule.Pack cT xclass.
Definition ringType := @Ring.Pack cT xclass.
End ClassDef.
Module Exports.
Coercion base : class_of >-> Ring.class_of.
Arguments mixin [R].
Coercion mixin : class_of >-> commutative.
Coercion sort : type >-> Sortclass.
Bind Scope ring_scope with sort.
Coercion eqType : type >-> Equality.type.
Canonical eqType.
Coercion choiceType : type >-> Choice.type.
Canonical choiceType.
Coercion zmodType : type >-> Zmodule.type.
Canonical zmodType.
Coercion ringType : type >-> Ring.type.
Canonical ringType.
Notation comRingType := type.
Notation ComRingType T m := (@pack T _ m _ _ id _ id).
Notation ComRingMixin := RingMixin.
Notation "[ 'comRingType' 'of' T 'for' cT ]" := (@clone T cT _ idfun)
(at level 0, format "[ 'comRingType'  'of'  T  'for'  cT ]") : form_scope.
Notation "[ 'comRingType' 'of' T ]" := (@clone T _ _ id)
(at level 0, format "[ 'comRingType'  'of'  T ]") : form_scope.
End Exports.
End ComRing.
Section ComRingTheory.
Variable R : comRingType.
Implicit Types x y : R.

Lemma mulrACA : @interchange R *%R *%R. Proof. exact: mulmACA. Qed.