We changed the abstract and keywords.
We fixed the Lean code since the previous code had returned a proposition statement instead of a proof.
I improved the Lean code.
Keyphrases: Euler's totient function, Goldbach's conjecture, prime numbers, sum-of-divisors function
@booklet{EasyChair:10824, author = {Frank Vega}, title = {Lean on Goldbach's Conjecture}, howpublished = {EasyChair Preprint 10824}, year = {EasyChair, 2023}}