FUNCTION: LieTools/UgLTWgt
USAGE: UgLTWgt(upoly);
SYNOPSIS: UgLTWgt(upoly) returns the weight (specified in terms of 
  a basis of simple roots) of the leading term of an
  element upoly in U(g). 
CAVEATS: requires a previously initialized global Lie algebra environment.
  (See LieTools[gSetup].)
EXAMPLE: 
> gSetup(G,2);
Setting up Gtype = G   rnk = 2
> UgLTWgt(3*u(g[1],g[2])+2*u(g[2],g[2]),G2);

                               [-6, -2]

SEE ALSO: LieTools[SgLTWgt]
