🚀 go-pugleaf

I was aware of the fact that 'RICCI' can do a lot of these things. However,
I also need to be able to substitute specific things into the components of
various tensors, and I do need a system that does automatic dummy relabeling,
not like 'RICCI' where the only way (correct me if I'm wrong) seems to
perform every substution after explicit relabeling by 'NewDummy'

  DefineTensor(a,1,Variance->Con)
  DefineTensor(b,1) 
  c=a[U[i]] b[L[i]]
  e=NewDummy[c] * Newdummy[c]

This is too complicated for the types of formulea I want to process.

MathTensor seems to be able to do all these things, but as it is commercial
and has a lot of things I really don't need, I'd still like to see something
in PD.

Thanks for the tip anyway,

Kasper