Description:

LiE purpose is to enable mathematicians and physicists to obtain on-line
information as well as to interactively perform computations of a Lie group
theoretic nature. It focuses on the representation theory of complex semisimple
(reductive) Lie groups and algebras, and on the structure of their Weyl
groups and root systems. The basic objects of computation are vectors and
matrices with integer entries, and polynomials with integral coefficients.
These objects are used to represent weights, (sets of) roots, characters and
similar objects relating to Lie groups and algebras. LiE does not compute
directly with elements of the Lie groups and algebras themselves, but the
computations may be parametrised by the type of the Lie group or algebra for
which they should be performed.