[zawerf]

I upvoted for Terry's very insightful meta-commentary on when partial results can or cannot help with the full proof: https://terrytao.wordpress.com/2019/09/10/almost-all-collatz...

I thought it was interesting how mathematician have techniques to easily prove something for the 99% case but still have the general problem be completely unapproachable.

(and because collatz is famous, terry is a fields medalist, etc)