Section Basics.
Variables (gT : finGroupType) (B : {set gT}) (S : seq 'CF(B)) (A : {set gT}).
Definition Zchar : {pred 'CF(B)} :=
[pred phi in 'CF(B, A) | dec_Cint_span (in_tuple S) phi].
Fact Zchar_key : pred_key Zchar. Proof. by []. Qed.
Canonical Zchar_keyed := KeyedPred Zchar_key.

Lemma cfun0_zchar : 0 \in Zchar.