Length Functions and HNN Groups
Faisal Nesayef · Journal of Scientific Research and Reports · 2017
The concept of length functions on groups is first introduced by Lyndon.This is used to give direct proofs of many other results in combinatorial group theory.Two important sets called M and N satisfying some certain axioms of length functions are considered.Finally investigations of the nature and the structures of the sets M and N in relation to the elements of HNN group were carried out.