FUNCTION: LieTools/fwgt2swgt
USAGE:  fwgt2swgt(fwgt,Gt); fwgt2swgt(fwgt); fwgt2swgt(fwgt,Gtype,rnk);
SYNOPSIS: Converts the components of a weight w.r.t. a basis of 
  fundamental weights to its components w.r.t. a basis of simple roots.
  If called with a single with a single argument fwgt, it is necessary that
  a global Lie algebra environment has been initialized. (See LieTools[gSetup].)
EXAMPLE: 
> fw := [0,1];
                             fw := [0, 1]

> sw := LieTools[fwgt2swgt](fw,G2);

                             cw := [3, 2]

> LieTools[swgt2fwgt](cw,G2);

                                [0, 1]


SEE ALSO: LieTools[swgt2fwgt], LieTools[CW2fwgt], LieTools[CW2swgt], LieTools[fwgt2CW],
          LieTools[CW2swgt],
           
