Published online by Cambridge University Press: 09 April 2009
The classification of groups according to the varieties they generate requires the study of a class of indecomposable elements. Such a class is the class of basic groups which have been studied in [4], [5] and [6]. A group is called basic if it is indecomposable qua group; that is, it is critical and indecomposable qua variety; that is, its variety is join-irreducible. In this note we consider the higher commutator structure of basic p-groups. Our main theme is the relation between the formal weight of the higher commutator subgroups and the class of the group. We obtain information about the power-commutator structure of a basic p-group, the kinds of laws that can hold in such a group and the varietal structure of groups of the form: Center-extended-by-X.