Arguments Aut _ _%g.
Notation "[ 'Aut' G ]" := (Aut_group G)
(at level 0, format "[ 'Aut'  G ]") : Group_scope.
Notation "[ 'Aut' G ]" := (Aut G)
(at level 0, only parsing) : group_scope.
Prenex Implicits Aut autm.
(* The permutation function (total on the underlying groupType) that is the *)
(* representant of a given morphism f with domain A in (Aut A).             *)
Section PermIn.
Variables (T : finType) (A : {set T}) (f : T -> T).
Hypotheses (injf : {in A &, injective f}) (sBf : f @: A \subset A).

Lemma perm_in_on : perm_on A perm_in.