proposition: Lemma TI_pcoreC pi G H : 'O_pi(G) :&: 'O_pi^'(H) = 1.
proof: Proof. by rewrite coprime_TIg ?coprime_pcoreC. 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)