Section InjmAut.
Variables (gT rT : finGroupType) (G D : {group gT}) (f : {morphism D >-> rT}).
Hypotheses (injf : 'injm f) (sGD : G \subset D).
Let domG := subsetP sGD.
Canonical conj_aut_morphism := Morphism conj_aut_morphM.
(* Characteristic subgroup properties : composition, relational properties *)

Lemma charY G H K : H \char G -> K \char G -> H <*> K \char G.