Arguments hom_mxP {m f W}.

(* Specifications: *)
Lemma hom_envelop_mxC m f (W : 'M_(m, n)) A :
(W <= dom_hom_mx f -> A \in E_G -> W *m A *m f = W *m f *m A)%MS.
Lemma dom_hom_invmx f :
f \in unitmx -> (dom_hom_mx (invmx f) :=: dom_hom_mx f *m f)%MS.
Lemma dom_hom_mx_module f : mxmodule (dom_hom_mx f).
Lemma hom_mxmodule m (U : 'M_(m, n)) f :
(U <= dom_hom_mx f)%MS -> mxmodule U -> mxmodule (U *m f).
Lemma kermx_hom_module m (U : 'M_(m, n)) f :
(U <= dom_hom_mx f)%MS -> mxmodule U -> mxmodule (U :&: kermx f)%MS.
Lemma scalar_mx_hom a m (U : 'M_(m, n)) : (U <= dom_hom_mx a%:M)%MS.
Definition rfix_mx (H : {set gT}) :=
let commrH := \matrix_(i < #|H|) mxvec (rG (enum_val i) - 1%:M) in
kermx (lin1_mx (mxvec \o mulmx commrH \o lin_mul_row)).