# PASCAL programs for identification of Lie algebras Part 3: LEVI decomposition and canonical basis

## Description

Title of program: LEVI Catalogue Id: AAXN_v1_0 Nature of problem Given a Lie algebra L with structure constants which are either integers or polynomials with integer coefficients, LEVI determines a LEVI decomposition of L into its radical R(L) and its (semi-)simple part S(L). The program CANONIK uses the methods of all three programs SPLIT, LEVI and RADICAL in order to express L in a standard basis: L is decomposed as a direct sum, each component L' is Levi-decomposed, each S(L') is decomposed as a direct sum, the nilradical of each r(l') is calculated, and f ... Versions of this program held in the CPC repository in Mendeley Data aaxn_v1_0; LEVI; 10.1016/0010-4655(87)90007-5 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)