T. Datuashvili
abstract:
The notion of central series for groups with action on itself is introduced. 
An analogue of Witt's construction is given for such groups. A certain condition 
is found for the action and the corresponding category is defined. It is proved 
that the above construction defines a functor from this category to the category 
of Lie-Leibniz algebras and in particular to Leibniz algebras; also the 
restriction of this functor on the category of groups leads us to Lie algebras 
and gives the result of Witt.