Abstract:
The structure of finite groups in which every proper subgroup is either $\mathfrak{F}$-subnormal or $\mathfrak{F}$-abnormal, where $\mathfrak{F}$ is a saturated hereditary formation with the Shemetkov property containing all nilpotent groups is studied. In particular, descriptions of these groups in the cases when $\mathfrak{F}$ is either the formation of all $p$-nilpotent groups or all $p$-decomposable groups were obtained.
Keywords:finite group, $\mathfrak{F}$-subnormal subgroup, $\mathfrak{F}$-abnormal subgroup, saturated formation, formation with the Shemetkov property.