I started using
xAct to perform some computations. I copied the xAct folder in the /.Mathematica/Applications folder in my Ubuntu system. I loaded it and created the manifold and defined the metric. The output however is not coming right on using the ordinary derivative PD.
PD[-a][PD[-b][T[c, d, -e]]]
Does anyone know how to resolve this? Also whenever I click the
xAct option in the Addons page of Mathematica, the screen freezes. I am using Mathematica 10.