FUNCTION: LieTools/Gr
USAGE: Gr(upoly);
SYNOPSIS: Gr is the gradation mapping from U[g] to S[g]

EXAMPLE: 
> upoly := 3*u(g[1],g[2],g[5],g[2],g[1])+u(g[3],g[2],g[1]);

   upoly := 3 u(g[1], g[2], g[5], g[2], g[1]) + u(g[3], g[2], g[1])

> LieTools[Gr](upoly);

                                2     2
                          3 g[1]  g[2]  g[5]

SEE ALSO: LieTools[UgDegree], LieTools[SymMap], LieTools[InvSymMap], 
          LieTools[NormalOrder] 
