fact: Definition center_Puig_char := BGappendixAB.center_Puig_char.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq div fintype finset) mathcomp(prime fingroup morphism automorphism quotient gproduct gfunctor) mathcomp(cyclic center commutator pgroup nilpotent sylow abelian hall) mathcomp(maximal) odd_order(BGsection1 BGappendixAB)