Does the ccgrg package work with Mathematica 12?

Questions
,
1

I have a number of notebooks written for whatever the current version was of Mathematica in 1990 and using the ccgrg package for general relativity. They now no longer work. There is no error, but the key functions such as tRicciR[a,b] that should give something like

In[243]:= tRicciR[1, 1]

Out[243]= (2 \[Alpha] \[Lambda] + x^2 \[Beta]^2 \[Lambda]^2 + 
   y^2 \[Beta]^2 \[Lambda]^2 + 4 z^2 \[Beta]^2 \[Lambda]^2 -

but just return “tRicciR[a,b]” rather than evaluating the function. Is this a known problem? And If there is no way to get ccgrg to run in 12, is there a way to resurrect the 1990 version of Mathematica? I’ve lost a lot of work if it is a dead package.

2

There is a ccgrg package available here. Revision date 2014-03-05.

3

That is the version that I have. It fails its self test as it does not seem to recognise the special characters that are used in the package.

4

Crossposted here.

5

ccgrg origially written for Mathematica 8 work properly with higher versions up to 11.1.

To run the package in higher versions of Mathematica you nead to restore the previous functionality of functions Solve and ValueQ. To do that please put in your notebook the following two lines:

If[$VersionNumber >= 12.2, SetOptions[ValueQ, Method -> "Legacy"]];
If[$VersionNumber >= 12.2, SetOptions[Solve, Assumptions -> {}]];

just after loading ccgrg.m.