Abstract:
Let $\Theta$ be a full modular lattice of the formation of finite groups
and let $0_\Theta$ be zero of $\Theta$. We say that a $\Theta$-formation
$\mathfrak F\ne 0_\Theta$ has the $\Theta$-length $l_\Theta(\mathfrak F)$ equal to
$n$ if there exist $\Theta$-formations
$$
\mathfrak F_0,\mathfrak F_1, \ldots,\mathfrak F_n
$$
such that $\mathfrak F_n=\mathfrak F$, $\mathfrak F_0=0_\Theta$, and
$\mathfrak F_{i-1}$ is a maximal $\Theta$-subformation of
$\mathfrak F_i$, $i=1,\ldots,n$. In this paper, a complete description
of the structure of composite formations of the $c$-length 3 is obtained.