End Mixin.
Definition pack_base T m :=
fun c cT & phant_id (Finite.class cT) c => @PackBase T m c.
Definition clone_base T :=
fun bT & sort bT -> T =>
fun m c (bT' := @PackBase T m c) & phant_id bT' bT => bT'.
Definition clone T :=
fun bT gT & sort bT * sort (base gT) -> T * T =>
fun m (gT' := @Pack bT m) & phant_id gT' gT => gT'.
Section InheritedClasses.
Variable bT : base_type.
Local Notation T := (arg_sort bT).
Local Notation rT := (sort bT).
Local Notation class := (finClass bT).
Canonical eqType := Equality.Pack class.
Canonical choiceType := Choice.Pack class.
Canonical countType := Countable.Pack class.
Canonical finType := Finite.Pack class.
Definition arg_eqType := Eval hnf in [eqType of T].
Definition arg_choiceType := Eval hnf in [choiceType of T].
Definition arg_countType := Eval hnf in [countType of T].
Definition arg_finType := Eval hnf in [finType of T].
End InheritedClasses.
Module Import Exports.
(* Declaring sort as a Coercion is clearly redundant; it only     *)
(* serves the purpose of eliding FinGroup.sort in the display of  *)
(* return types. The warning could be eliminated by using the     *)
(* functor trick to replace Sortclass by a dummy target.          *)
Coercion arg_sort : base_type >-> Sortclass.
Coercion sort : base_type >-> Sortclass.
Coercion mixin : base_type >-> mixin_of.
Coercion base : type >-> base_type.
Canonical eqType.
Canonical choiceType.
Canonical countType.
Canonical finType.
Coercion arg_eqType : base_type >-> Equality.type.
Canonical arg_eqType.
Coercion arg_choiceType : base_type >-> Choice.type.
Canonical arg_choiceType.
Coercion arg_countType : base_type >-> Countable.type.
Canonical arg_countType.
Coercion arg_finType : base_type >-> Finite.type.
Canonical arg_finType.
Bind Scope group_scope with sort.
Bind Scope group_scope with arg_sort.
Notation baseFinGroupType := base_type.
Notation finGroupType := type.
Notation BaseFinGroupType T m := (@pack_base T m _ _ id).
Notation FinGroupType := Pack.
Notation "[ 'baseFinGroupType' 'of' T ]" := (@clone_base T _ id _ _ id)
(at level 0, format "[ 'baseFinGroupType'  'of'  T ]") : form_scope.
Notation "[ 'finGroupType' 'of' T ]" := (@clone T _ _ id _ id)
(at level 0, format "[ 'finGroupType'  'of'  T ]") : form_scope.
End Exports.
End FinGroup.
Export FinGroup.Exports.
Section ElementOps.
Variable T : baseFinGroupType.
Notation rT := (FinGroup.sort T).
Definition oneg : rT := FinGroup.one T.
Definition mulg : T -> T -> rT := FinGroup.mul T.
Definition invg : T -> rT := FinGroup.inv T.
Definition expgn_rec (x : T) n : rT := iterop n mulg x oneg.
End ElementOps.
Definition expgn := nosimpl expgn_rec.
Notation "1" := (oneg _) : group_scope.
Notation "x1 * x2" := (mulg x1 x2) : group_scope.
Notation "x ^-1" := (invg x) : group_scope.
Notation "x ^+ n" := (expgn x n) : group_scope.
Notation "x ^- n" := (x ^+ n)^-1 : group_scope.
(* Arguments of conjg are restricted to true groups to avoid an *)
(* improper interpretation of A ^ B with A and B sets, namely:  *)
(*       {x^-1 * (y * z) | y \in A, x, z \in B}                 *)
Definition conjg (T : finGroupType) (x y : T) := y^-1 * (x * y).
Notation "x1 ^ x2" := (conjg x1 x2) : group_scope.
Definition commg (T : finGroupType) (x y : T) := x^-1 * x ^ y.
Notation "[ ~ x1 , x2 , .. , xn ]" := (commg .. (commg x1 x2) .. xn)
: group_scope.
Prenex Implicits mulg invg expgn conjg commg.
Notation "\prod_ ( i <- r | P ) F" :=
(\big[mulg/1]_(i <- r | P%B) F%g) : group_scope.
Notation "\prod_ ( i <- r ) F" :=
(\big[mulg/1]_(i <- r) F%g) : group_scope.
Notation "\prod_ ( m <= i < n | P ) F" :=
(\big[mulg/1]_(m <= i < n | P%B) F%g) : group_scope.
Notation "\prod_ ( m <= i < n ) F" :=
(\big[mulg/1]_(m <= i < n) F%g) : group_scope.
Notation "\prod_ ( i | P ) F" :=
(\big[mulg/1]_(i | P%B) F%g) : group_scope.
Notation "\prod_ i F" :=
(\big[mulg/1]_i F%g) : group_scope.
Notation "\prod_ ( i : t | P ) F" :=
(\big[mulg/1]_(i : t | P%B) F%g) (only parsing) : group_scope.
Notation "\prod_ ( i : t ) F" :=
(\big[mulg/1]_(i : t) F%g) (only parsing) : group_scope.
Notation "\prod_ ( i < n | P ) F" :=
(\big[mulg/1]_(i < n | P%B) F%g) : group_scope.
Notation "\prod_ ( i < n ) F" :=
(\big[mulg/1]_(i < n) F%g) : group_scope.
Notation "\prod_ ( i 'in' A | P ) F" :=
(\big[mulg/1]_(i in A | P%B) F%g) : group_scope.
Notation "\prod_ ( i 'in' A ) F" :=
(\big[mulg/1]_(i in A) F%g) : group_scope.
Section PreGroupIdentities.
Variable T : baseFinGroupType.
Implicit Types x y z : T.
Local Notation mulgT := (@mulg T).

Lemma invMg x y : (x * y)^-1 = y^-1 * x^-1. Proof. by case: T x y => ? []. Qed.