Name: rolf Date: 06/21/05-02:27:32 AM Z


Hi,
you can get a result without $MU’s by doing:

DiracEquation[
  DotExpand[
    DiracGammaExpand[
      Expand[Contract[DotExpand[Contract[MomentumCombine2[Contract[M]]]]]]]]]

However, the result can be simplified by renaming
the indices ( c <–> d ), as you would do by hand.

That is what I have automatized (which was actually quite non-trivial, especially if there are higher tensors involced) in DiracSimplify (which is used in Calc), and the dummy indices generated are called $MU[…] .

Regards,

Rolf Mertig
GluonVision GmbH
Berlin, Germany
Mathematica training & consulting