FUNCTION: LieTools/C2FDR
USAGE: C2FDR(hfw,Gt); C2FDR(hfw); C2FDR(hfw,Gtype,rnk);
SYNOPSIS: C2FDR(hfw,Gt) computes the value of 
          <hfw+rho,hfw+rho> - <rho,rho> 
  which should, up to a constant scalar multiple coincide with
  the value of the 2nd order Casimir operator on the irreducible
  finite dimensional representation of g with highest weight hfw 
  (specified in terms of a basis of fundamental weights).
REMARK: C2FDR can also be called with a single argument hfw if the
  global Lie algebra environment. (See LieTools[gSetup].)


SEE ALSO: 
