proposition: Lemma NirrSn n : Nirr 'SG_n = #|{:'P_n}|.
proof: Proof. Proof using. by rewrite NirrE card_classes_perm card_ord. 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