FUNCTION: LieTools/SgMonoWgt
USAGE: SgMonoWgt(gmono);
SYNOPSIS: SgMonoWgt(gmono) returns the weight of a monomial gmono in S[g]
  w.r.t.to a basis of simple weigts
CAVEATS: requires a previously initialized global Lie algebra environment.
  (See LieTools[gSetup].)
EXAMPLE: 
> gSetup(A,3);
Setting up Gtype = A   rnk = 3
> SgMonoWgt(g[1]^3);

                             [-3, -3, -3]

> swgt2fwgt(%);

                             [-3, 0, -3]

SEE ALSO: LieTools[SgMonoSortByWgt]
