FUNCTION: LieTools/Euler
USAGE: Euler(gpoly);
SYNOPSIS: Euler(gpoly) computes the action of the Euler operator
    sum(g[i]*diff(gpoly),g[i],i=1..dimg)
  on a polynomial in S(g).
CAVEATS: requires a previously initialized global Lie algebra environment.
  (See LieTools[gSetup].)
EXAMPLE: 
> LieTools[gSetup](G,2);
Setting up Gtype = G   rnk = 2
> LieTools[Euler](g[1]*g[3]^2);

                                        2
                             3 g[1] g[3]


SEE ALSO: LieTools[SgLaplacian], LieTools[SgC2], LieTools[Dg]
