If I enter ex:= -\frac{2}{3} \indexbracket{ (\theta \Gamma_{m} \chi2)};
XCadabra 1.39 (on Linux 16.04) shows above without the factor of -2/3 . How to get this factor?
You may want to upgrade to 2.x, where this works fine. If you can't do that, can you explain what is stopping you? (e.g. some feature which is broken/missing in 2.x but working in 1.x).
I tried my problem in 2.x but couldn't continue because of the issue with combine algorithm. I asked about these here,
https://cadabra.science/qa/687/combine-algorith-for-gamma-matrices and https://cadabra.science/qa/667/possible-issue-with-combine-algorithm
It would be great if these are fixed.
Thanks