FUNCTION: LieTools/UgInsertMono
USAGE: UgInsertMono(umono,ulist);
SYNOPSIS: UgInsertMono(umono,ulist) inserts a monomial in U(g) into an ordered 
  list of monomials in U(g) in such a way that the graded lecicographic order of the
  corresponding monomials in S(g) is preserved.

EXAMPLE: 
> ulist := [ u(g[4],g[11]), u(g[2],g[13]), u(g[1],g[12],g[5])];

   ulist := [u(g[4], g[11]), u(g[2], g[13]), u(g[1], g[12], g[5])]

> slist := []:
> for i from 1 to nops(ulist) do slist := UgInsertMono(op(i,ulist),slist); od;

                      slist := [u(g[4], g[11])]


              slist := [u(g[2], g[13]), u(g[4], g[11])]


   slist := [u(g[2], g[13]), u(g[4], g[11]), u(g[1], g[12], g[5])]

SEE ALSO: 
