FUNCTION: LieTools/NormalOrder
USAGE: NormalOrder(gpoly);
SYNOPSIS: NormalOrder(gpoly) maps a polynomial x in S[g] to a normal-ordered
  element in U[g] (monomials in S[g] are mapped to PBW basis elements)
CAVEATS: requires a previously initialized global Lie algebra environment.
  (See LieTools[gSetup].)
EXAMPLE: 
> gSetup(G,2);
Setting up Gtype = G   rnk = 2
> gpoly := expand((g[1]+g[2])^3);

                      3         2                   2       3
         gpoly := g[1]  + 3 g[1]  g[2] + 3 g[1] g[2]  + g[2]

> NormalOrder(gpoly);

  u(g[1], g[1], g[1]) + 3 u(g[1], g[1], g[2]) + 3 u(g[1], g[2], g[2])

         + u(g[2], g[2], g[2])


SEE ALSO: LieTools[SymMap], LieTools[Gr],
