  
  
  [1XReferences[101X
  
  [[20XEN02[120X]  [16XEick,  B.  and  Nickel,  W.[116X, [17XPolycyclic, Algorithms for working with
  polycyclic          groups[117X          (2002),          (GAP          package),
  https://gap-packages.github.io/polycyclic/.
  
  [[20XGMP[120X] [17XGNU MP[117X, https://gmplib.org/.
  
  [[20XHig59[120X]  [16XHigman,  G.[116X,  [17XSome  remarks on varieties of groups[117X, [18XQuart. J. Math.
  Oxford[118X, [19X2[119X, 10 (1959), 165–178.
  
  [[20XLS90[120X] [16XLeedham-Green, C. R. and Soicher, L. H.[116X, [17XCollection from the left and
  other strategies[117X, [18XJ. Symbolic Comput.[118X, [19X9[119X, 5–6 (1990), 665–675.
  
  [[20XNic96[120X]  [16XNickel,  W.[116X,  [17XComputing  Nilpotent  Quotients of Finitely Presented
  Groups[117X,  in  Geometric  and  Computational  Perspectives on Infinite Groups,
  Dimacs  Series  in Discrete Mathematics and Theoretical Computer Science, [19X25[119X
  (1996), 175–191.
  
  [[20XNN94[120X] [16XNewman, M. F. and Nickel, W.[116X, [17XEngel elements in groups[117X, [18XJ. Pure Appl.
  Algebra[118X, [19X96[119X (1994), 39–45.
  
  [[20XSim94[120X]  [16XSims,  C. C.[116X, [17XComputation with Finitely Presented Groups[117X, Cambridge
  University Press (1994).
  
  [[20XVau90[120X]  [16XVaughan-Lee,  M. R.[116X, [17XCollection from the Left[117X, [18XJ. Symbolic Comput.[118X,
  Academic Press, [19X9[119X (1990), 725–733.
  
  
  
  [32X
