Hi,
I was learning how to use the Fierz identity using the manual and a notebook in tutorials.
(Eventually, I understood why I got stuck with it: I was sloppy on mentioning the range of the indices explicitly. Sorry, Kasper.)
Anyway,
I found a typo in the tutorial of Fierz transformations:
fierz(_, $\theta, \epsilon, \psi_{\mu}, \psi_{\nu}$ );
should be replaced with
fierz(_, $\theta, \epsilon, \psi_{\mu}, \psi_{\rho}$ );
This is what I got stuck with for a while :) Thanks.