Section FpRow.
Variables p n : nat.
Local Notation rVn := 'rV['F_p]_n.
End FpRow.
Variables (p : nat) (gT : finGroupType) (E : {group gT}).
Hypotheses (abelE : p.-abelem E) (ntE : E :!=: 1%g).
Let pE : p.-group E := abelem_pgroup abelE.
Let p_pr : prime p. Proof. by have [] := pgroup_pdiv pE ntE. Qed.
Local Notation n' := (abelem_dim' (gval E)).
Local Notation n := n'.+1.
Local Notation rVn := 'rV['F_p](gval E).
Local Notation ab_rV_P := (existsP isog_abelem_rV).
Definition abelem_rV : gT -> rVn := xchoose ab_rV_P.
Local Notation ErV := abelem_rV.
Canonical abelem_mx_linear g := Linear (abelem_mx_linear_proof g).
Let rVabelemJmx v x : x \in G -> rV_E (v *m r x) = (rV_E v) ^ x.
Fact abelem_mx_repr : mx_repr G r.
Canonical abelem_repr := MxRepresentation abelem_mx_repr.
Let rG := abelem_repr.

Lemma rfix_abelem (H : {set gT}) :
H \subset G -> (rfix_mx rG H :=: rowg_mx (ErV @* 'C_E(H)%g))%MS.