Abstract
If α denotes the class of all QTAG-modules
such that
is totally projective for every ordinal
, then these modules are called α-modules. Here we study the relation between the structure of fully invariant submodules of certain QTAG-modules and the structure of containing modules. It is found that if
is a fully invariant submodule of the totally projective QTAG-module
, then both
and
are totally projective. We show that if for some sequence
, both
and
are totally projective, then
itself is necessarily totally projective.