[nabajour]

If the issue is a lack of way to structure the explanation or missing the justification to go from one step to the next, having a structure that forces one to be explicit helps.

Other than sympy, a technique for formal proof might help.

One of my buddies showed me this talk from Leslie Lamport that I found interesting [1], albeit in french. I think this one [2] is an english version. And the paper behind is here [3], linked from Lamport's website [4].

Lamport makes a structured way to write proof so that all details can be written down. It seemed to me that a lot of knowledge and steps stay implicit in proofs. So if you're not familiar with the subject, you easily get lost.

[1] https://www.youtube.com/watch?v=k-i7y0R_-KE

[2] https://www.youtube.com/watch?v=uBiJpip9NVc

[3] http://lamport.azurewebsites.net/pubs/proof.pdf

[4] http://lamport.org/

edit: fixed links and text structure