proposition: Lemma sign_Chi2 : mx_rsim sign_repr 'Chi_(cast_ord (esym NirrS2) 1).
proof: Proof. Proof using. by apply/cfRepr_rsimP; rewrite cfRepr_sign2 irrRepr. Qed.
imports: mathcomp(all_ssreflect) mathcomp(fingroup perm ssralg morphism perm action) mathcomp(zmodp) mathcomp(vector matrix mxalgebra ssrnum algC) mathcomp(mxrepresentation classfun character) permcomp tools partition congr cycles cycletype presentSn