Section ChangeGroup.
Variables (gT : finGroupType) (G H : {group gT}) (n : nat).
Variables (rG : mx_representation F G n).
Section SubGroup.
Hypothesis sHG : H \subset G.
Local Notation rH := (subg_repr rG sHG).

(* Specifications: *)
Lemma rfix_subg : rfix_mx rH = rfix_mx rG. Proof. by []. Qed.
Section Stabilisers.