proposition: Fact cymapcan_aux (x : U) : V.
proof: Proof. Proof using CM. have : fs CM (porbit s x) != set0. rewrite -card_gt0 fs_homog ?imset_f // card_gt0. by apply/set0Pn; exists x. by move/set0Pn/sigW => H; apply H. 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