proposition: Lemma morph_generator A : generator A x -> generator (f @* A) (f x).
proof: Proof. by move/(A =P _)->; rewrite /generator morphim_cycle. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice div) mathcomp(fintype bigop prime finset fingroup morphism) mathcomp(perm automorphism quotient gproduct ssralg) mathcomp(finalg zmodp poly)