Expanding the Einstein Tensor into Christoffels

[saffe...@gmail.com]

Hello,

I am having an issue when it comes to expanding out the Einstein tensor to Christoffels, and then applying ToCanonical.

When I attempt to expand:

EinsteinCD[a,b] //EinsteinToRicci //RiemannToChristoffel //ChristoffelToGradMetric //ToCanonical

I get thrown an error SymmetryOf:: nouse

I've traced the error down to applying the RiemannToChristoffel on the RicciScalarCD[] term.  This generates an expression encompassed in red parentheses.  When contracted with the metric, a double counting of indices appears (See the attached screenshot).  

I get the same error when I attempt to run the identical line of code from the xTensorDoc.nb file.

I'm thinking it may have something to do with my system, but I'm not 100% sure as I'm still new with xAct.  I'm using a Mac version 10.11.6.  Any clues as to what may be causing this?

Thanks,

Alex

[saffe...@gmail.com]

Thank you Pedram.

EinsteinCD[a,b] //EinsteinToRicci //RiemannToChristoffel //ChristoffelToGradMetric //NoScalar //ToCanonical  works

The issue had to do with the scalar head definition in the RicciScalarCD[] term.  By assigning NoScalar, the scalar head is removed and new indices are assigned.  I also noticed Leo had answered this question in a previous post, but I had not understood enough about scalar heads to figure out what he was saying.