Name: Rolf Mertig Date: 06/30/05-06:39:30 PM Z


Strange.
Which Operating System and which Mathematica
Version are you using?
For me it just works:

rolfm@gluon:~> math
Mathematica 5.1 for Linux x86 (64 bit)
Copyright 1988-2004 Wolfram Research, Inc.
 – Motif graphics initialized –

In[1]:= «HighEnergyPhysics`FeynCalc`

In[2]:= $FeynCalcDirectory

Out[2]= /home/rolfm/.Mathematica/Applications/HighEnergyPhysics

In[3]:= $FeynCalcVersion

Out[3]= 5.1.0beta1

In[4]:= Tr[GS[a,b,c,d]]

Out[4]= 4 (a.d b.c - a.c b.d + a.b c.d)