proposition: Lemma porbit_cymap x : porbit t (cymap x) = CM (porbit s x).
proof: Proof. Proof using. by rewrite /cymap porbit_perm porbit_cymapcan. 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