Section ChangeGroup.
Variables (gT : finGroupType) (G H : {group gT}) (n : nat).
Variables (rG : mx_representation G n).
Section SubGroup.
Hypothesis sHG : H \subset G.

(* Specifications: *)
Lemma subg_mx_repr : mx_repr H rG.
Definition subg_repr := MxRepresentation subg_mx_repr.