Busy beaver for Fractran
https://en.wikipedia.org/wiki/FRACTRAN
https://wiki.bbchallenge.org/wiki/Fractran
Enumerate sz23.
Look at Minsky machines.
Write a new decider. The decider should satisfy these requirements:
- When given a Fractran program in
sz22_2003_unofficial.txt, the decider must return either "halt", "non-halt", or "undecided". - When given a Fractran program in
sz22_halted_689.txt, the decider must return either "halt" or "undecided". In particular, the decider must not return "non-halt". - The decider must return "non-halt" on at least 5% of holdouts in
sz22_2003_unofficial.txt, or return "halt" on at least 1 holdout. - The decider must take at most 1 hour per holdout when run on reasonable hardware.
There are deciders in decider/*.py. However, these deciders won't decide any holdouts in sz22_2003_unofficial.txt. You will have to either upgrade an existing decider or write a new decider from scratch.
(Note: Claude Opus 4.6 was unable to write a new decider after a few tries. Let's try again in a few years...)