ABSTRACT
Crq-groups proved to be tractable, and extensive detailed information about these groups could be obtained (Chapter 6 ). It is natural to look for generalizations. Surprisingly, the basic results such as the description of crq-groups (Lemma 3.1.1), the useful purification lemma (Lemma 3.1.2), the regulating subgroup criterion (Theorem 6.2.2), and many more do generalize. In these generalizations integers are replaced by integral matrices, and while integral matrices are considerably more complicated than integers, powerful tools exist in the computer algebra system Maple (for example) that make it possible to let the computer do the dirty work. The results of this chapter first appeared in [B096a], [BM98a], and [BM98b].
