AllContractions not working

[Sukruti]

Hello,

Any idea why the command AllContractions is not working in the attached notebook and how to make it work?

Best,

Sukruti

[Jose]

Hi,

I suspect the problem is that AllContractions does not work on sums. I think it wants just products of tensors. According to its documentation, it takes a list of tensors, so you can perhaps first convert the sum of terms into a list of terms (with Apply[List, sum] for example) and then pass this list to AllContractions.

Cheers,

Jose.

[Sukruti]

Hello,

I have deleted my last few emails in this thread because I was a bit too quick in posting them. I now summarise my conclusion on Jose's suggestion of converting the sum of terms into a list of terms with Apply[List, sum].

This suggestion is useful for employing the AllContractions command. A caveat is that on generating the sum of original terms, some of the terms appearing in the resulting sum might have one or more pairs of contracted indices. It would require spotting those terms and replacing one of the indices in a given pair of contracted indices with a new index and then applying AllContractions on such terms.

Cheers

Sukruti