Definition cfclass (A : {set gT}) (phi : 'CF(A)) (B : {set gT}) :=
[seq (phi ^ repr Tx)%CF | Tx in rcosets 'I_B[phi] B].
Local Notation "phi ^: G" := (cfclass phi G) : cfun_scope.

Lemma card_cfclass_Iirr i : H <| G -> #|cfclass_Iirr G i| = #|G : 'I_G['chi_i]|.