Lie polynomial
= Lie polynomial
{c}
A finite linear combination of iterated <Lie brackets> in formal variables. It evaluates naturally in every <Lie algebra>, and every <Lie algebra homomorphism> preserves its evaluation. The homogeneous terms of the <Baker--Campbell--Hausdorff formula> are rational Lie polynomials; this permits the group law to be reconstructed from the bracket wherever the series converges.