ON 𝔛-SATURATED FORMATIONS OF FINITE GROUPS#.

In the paper, a Frattini-like subgroup associated with a class ?? of simple groups is introduced and analyzed. The corresponding ??-saturated formations are exactly the ??-local ones introduced by Förster. Our techniques are also useful to highlight the properties and behavior of ?-local formations. In fact, extensions and improvements of several results of Shemetkov are natural consequences of our study. [ABSTRACT FROM AUTHOR]