author: | Csaba Schneider |
title: | Computing nilpotent quotients in finitely presented Lie rings |
keywords: | Lie rings nilpotent Lie rings finitely presented Lie rings nilpotent presentation
|
abstract: | A nilpotent quotient algorithm for finitely presented Lie rings over Z (and Q) is described. The paper studies the graded
and non-graded cases separately. The algorithm computes the so-called nilpotent
presentation for a finitely presented, nilpotent Lie ring. A nilpotent
presentation consists of generators for the abelian group and the products
expressed as linear combinations for pairs formed by generators. Using that
presentation the word problem is decidable in L. Provided that the Lie ring
L is graded, it is possible to determine the canonical presentation for a
lower central factor of L. Complexity is studied and it is shown that optimising
the presentation is NP-hard. Computational details are provided with examples,
timing and some structure theorems obtained from computations. Implementation
in C and GAP interface are available.
|
reference: |
Csaba Schneider (1997),
Computing nilpotent quotients in finitely presented Lie rings,
Discrete Mathematics and Theoretical Computer Science 1, pp. 1-16 |
ps.gz-source: | dm010101.ps.gz |
ps-source: | dm010101.ps (390 K) |
pdf-source: | dm010101.pdf (191 K) |