ABSTRACT
Extending an idea of Bass, one can construct a large torsion-free group y(A) of units in the integral group ring 핫A of any finite abelian group A. This group of constructible units is “good” in two ways: it easily allows the selection of explicit sets of independent generators (bases), and it is typically of low (often trivial) index in the the full unit group of 핫A. The present paper deals with cases where Y(A) does not suffice to describe the full unit group, but where it is nevertheless possible to produce bases of the latter by using constructible units together with co-induced ones.
