Fermat was actually able to prove Fermat's Last Theorem but just for n=4

So many submissions, so little discussion:

https://news.ycombinator.com/item?id=16047869

https://news.ycombinator.com/item?id=15960818

https://news.ycombinator.com/item?id=15932828

https://news.ycombinator.com/item?id=15923035

https://news.ycombinator.com/item?id=15916719

https://news.ycombinator.com/item?id=15906132