Skelet's 43 holdouts
Skelet's 43 holdouts are 43 different 5-state, 2-symbol machines made public by Skelet in 2003. These machines are derived from a set of 164 machines that were left undecided by Skelet's bbfind program, which classified all other 5-state, 2-symbol machines into either halting or non-halting.[1] Due to the length and lack of comments in bbfind's source code, Skelet's work is believed to not have been independently verified.[2] It is now known that all 43 of these holdouts do not halt.[3]
Other work done in bbfind includes computing the correct value of BB(4).[1]
https://bbchallenge.org/skelet
- ↑ 1.0 1.1 Skelet, "Busy Beaver prover" (2003). Accessed 29 August 2024.
- ↑ "Story" (section "Skelet's 43 undecided machines").
- ↑ "Skelet’s 43 machines".