Анотація:
The infinite groups, in which there is no any infinite descending chain of non-invariant decomposable abelian subgroups (md-groups) are studied. Infinite groups with the minimal
condition for non-invariant abelian subgroups, infinite groups with
the condition of normality for all decomposable abelian subgroups
and others belong to the class of md-groups. The complete description of infinite locally finite and locally soluble non-periodic
md-groups is given, the connection of the class of md-groups with
other classes of groups are investigated.