TMBR: June 2026
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This edition of TMBR is in progress and has not yet been released. Please add any notes you think may be relevant (including in the form a of a TODO with a link to any relevant Discord discussion).
BB Adjacent
Busy Beaver for Lambda Calculus:
- TODO: BBλ(39) solved
- New champions were discovered for Ξ₀(10), Ξ₀(13), Ξ₀(14), Ξ₀(15), Ξ₀(16), Ξ₀(17), Ξ₀(18) and Ξ₀(19).
- New SK calculus champions were discovered for Ξ₀_SK(18) and Ξ₀_SK(26).
- New BCKW system champions were discovered for Ξ₀_BCKW(7), Ξ₀_BCKW(8) and Ξ₀_BCKW(9).
Misc
- TODO: GPU deciders
Holdouts
- BB(6)
- mxdys solved four TMs with FAR.[1][2][3][4]
- prurq solved another four TMs with FAR.[5][6][7]
- A TM was shown to be non-halting by hipparcos, which was later confirmed in Rocq by mxdys.
- BB(2,6)
- Andrew Ducharme reduced the number of holdouts from 413,513 to 412,086, a 0.35% reduction.[8]
- BB(2,7)
- Terry Ligocki enumerated 100K more subtasks, increasing the number of holdouts to 1,392,222,673. A total of 450K subtasks out of the 1 million subtasks (or 45%) have been enumerated.