Section DetRepr.
Variables (n : nat) (rG : mx_representation [fieldType of algC] G n).
Definition det_repr_mx x : 'M_1 := (\det (rG x))%:M.
Fact det_is_repr : mx_repr G det_repr_mx.
Canonical det_repr := MxRepresentation det_is_repr.
Definition detRepr := cfRepr det_repr.
End DetRepr.
Definition cfDet phi := \prod_i detRepr 'Chi_i ^+ truncC '[phi, 'chi[G]_i].

Lemma cfDetRepr n rG : cfDet (cfRepr rG) = @detRepr n rG.