proposition: Lemma group_set_rotations : group_set rotations.
proof: Proof. by rewrite -rot_is_rot group_set_rot. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq div) mathcomp(choice fintype tuple finfun bigop finset fingroup) mathcomp(action perm primitive_action)