You're looking at Less Wrong's discussion board. This includes all posts, including those that haven't been promoted to the front page yet. For more information, see About Less Wrong.

Douglas_Knight comments on Open thread, August 26 - September 1, 2013 - Less Wrong Discussion

3 Post author: philh 26 August 2013 09:00PM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (148)

You are viewing a single comment's thread. Show more comments above.

Comment author: Douglas_Knight 30 August 2013 08:51:24PM 3 points [-]

The inverse of the Ackermann function grows very slowly but is not primitive recursive. That is, the function f where f(n) is the smallest m such that A(m) exceeds n. Of course, this is hardly a different method of proof.