proposition: Lemma quotient_pcore_mod pi gT (G : {group gT}) (B : {set gT}) : pcore_mod G pi B / B = 'O_pi(G / B).
proof: Proof. exact/morphpreK/gFsub_trans/morphim_sub. 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)