Name: Rolf Mertig Date: 01/13/12-12:14:17 PM Z


This is not wrong, just inconvenient.
Remember that CA and CF are not independent, so the result SUNSimplify
gives (if the option SUNNToCACF is set to True) is kind of heuristic.

This gives 0 :

Expand[SUNSimplify[SUNT[a, b, b, a] + SUNT[a, b, a, b]] -
    (SUNSimplify[SUNT[a, b, b, a]] +
     SUNSimplify[SUNT[a, b, a, b]]) /.
   {CA -> SUNN, CF -> (SUNN^2 - 1)/(2*SUNN)}]

Rolf