proposition: Lemma fiber_slporbitE (T : finType) (s : {perm T}) i : #|fiber (slporbits s) i| = count_mem i (cycle_type s).
proof: Proof. Proof using. by rewrite -card_pred_card_porbits /fiber /= imset_id. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice fintype) mathcomp(tuple finfun finset path bigop) mathcomp(fingroup perm action) mathcomp(ssralg matrix mxalgebra algC classfun) partition tools sorted permcomp fibered_set cycles