On factor groups of some groups

Анотація

Let for a prime p, X (respectively Y) be the class of all p-biprimitively finite (respectively periodic p-conjugatively biprimitively finite) groups and G∈X (respectively G∈Y), V be a periodic subgroup of G having an ascending series of normal in G subgroups such that each its factor is an almost layer-finite group or a locally graded group of finite special rank, or a WF-group with min-q on all primes q. We prove that G/V∈X (respectively G/V∈Y). Also some interesting and useful preliminary results are obtained.