proposition: Lemma pcore_mod_sub pi gT (G : {group gT}) : pcore_mod G pi (F _ G) \subset G.
proof: Proof. by rewrite sub_morphpre_im ?gFsub_trans ?morphimS ?gFnorm //= ker_coset gFsub. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq div) mathcomp(fintype bigop finset prime fingroup morphism) mathcomp(gfunctor automorphism quotient action gproduct) mathcomp(cyclic)