Generators and relations for wreath products

Generators and defining relations for wreath products of groups are given. Under a certain condition (conormality of generators), they are minimal.Наведено твірні та визначальні співвідношення для вінцевих добутків. За деякої умови (конормальність твірних) вони є мінімальними

One branch curve singularities with at most 2-parameter families of ideals

A criterion is given in order that the ideals of a one branch curve singularity form at most 2-parameter families. Namely, we present a list of plane curve singularities from the Arnold's classification which are the smallest among all one branch singularities having at most 2-parameter families of ideals