Published online by Cambridge University Press: 20 November 2018
It is known that the $K$-groups that appear in the calculation of the $K$-theory of a large class of groups can be computed from the $K$-theory of their virtually infinite cyclic subgroups. On the other hand, Nil-groups appear to be the obstacle in calculations involving the $K$-theory of the latter. The main difficulty in the calculation of Nil-groups is that they are infinitely generated when they do not vanish. We develop methods for computing the exponent of $\text{N}{{\text{K}}_{0}}$-groups that appear in the calculation of the ${{K}_{0}}$-groups of virtually infinite cyclic groups.