End AutIn.
Arguments Aut_in {gT} A%g B%g.
Section InjmAutIn.
Variables (gT rT : finGroupType) (D G H : {group gT}) (f : {morphism D >-> rT}).
Hypotheses (injf : 'injm f) (sGD : G \subset D) (sHG : H \subset G).
Let sHD := subset_trans sHG sGD.
Local Notation fGisom := (Aut_isom injf sGD).
Local Notation fHisom := (Aut_isom injf sHD).
Local Notation inH := (restr_perm H).
Local Notation infH := (restr_perm (f @* H)).

Lemma injm_Aut_sub : Aut_in (Aut (f @* G)) (f @* H) \isog Aut_in (Aut G) H.