TMBR: May 2026: Difference between revisions

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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).''
''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 ==
[[General Recursive Function|General Recursive Functions]]:
* Some new cryptids were hand-built:
** Size 56, by Shawn on 2 May (simulating 5x+1 problem starting at 7).<sup>[https://github.com/sligocki/etc/blob/main/gen_rec/mgrf/collatz.mgrf]</sup>
** Size 49, by aparker, star and Shawn on 3 May (simulating [[wikipedia:Brocard's_problem|Brocard's problem]]).<sup>[https://github.com/sligocki/etc/blob/main/gen_rec/mgrf/brocard.mgrf]</sup>
* The first non-trivial divergent GRF was found (size 15). It halts iff there exists some n ≥ 1 such that n+3 divides <math>Tetr(n) = \frac{n(n+1)(n+2)}{6}</math>.<sup>[https://discord.com/channels/960643023006490684/960643023530762341/1500584497542987776]</sup> aparker<sup>[https://discord.com/channels/960643023006490684/960643023530762341/1500587569514283098]</sup> and star<sup>[https://discord.com/channels/960643023006490684/960643023530762341/1500595210919346337]</sup> proved that there is no such n.
== Misc ==
* mxdys made [https://github.com/ccz181078/busycoq/blob/BB6/verify/Inductive_inf.v his inductive decider] for [[History linear|history-linear]] machines compilable into an executable file.<sup>[https://discord.com/channels/960643023006490684/960655108578881597/1501260508051800318]</sup>


== Holdouts ==
== Holdouts ==
 
*[[BB(4,3)]]
**Andrew Ducharme reduced the number of holdouts from 5,641,006 to '''5,127,263''', a '''9.11%''' reduction, with mxdys's new inductive decider.<sup>[https://discord.com/channels/960643023006490684/1084047886494470185/1502750172407533628]</sup>
*[[BB(2,6)]]
*[[BB(2,6)]]
**Andrew Ducharme reduced the number of holdouts from 536,112 to '''533,764''' via Enumerate.py, a '''0.44%''' reduction.<sup>[https://discord.com/channels/960643023006490684/1084047886494470185/1500218448951775383]</sup>
**Andrew Ducharme reduced the number of holdouts from 536,112 to '''527,232''' via Enumerate.py and TM-enum, a '''1.66%''' reduction.<sup>[https://discord.com/channels/960643023006490684/1084047886494470185/1500218448951775383][https://discord.com/channels/960643023006490684/1084047886494470185/1501436678823477368]</sup>
**Using the new inductive decider by mxdys and TM-enum, Andrew Ducharme first reduced the number of holdouts from 527,232 to '''501,914'''<sup>[https://discord.com/channels/960643023006490684/1084047886494470185/1501664852953792513][https://discord.com/channels/960643023006490684/1084047886494470185/1501812428113973268]</sup>, then to '''439,120''' again using the inductive decider.<sup>[https://discord.com/channels/960643023006490684/1084047886494470185/1502436063103291492]</sup> In total this was a '''16.71%''' reduction.
*[[BB(2,7)]]
*[[BB(2,7)]]
** Terry Ligocki enumerated 20K more subtasks, increasing the number of holdouts to  '''749,156,843'''. A total of 24K subtasks out of the 1 million subtasks (or '''24%''') have been enumerated.<sup>[https://discord.com/channels/960643023006490684/1084047886494470185/1492652604088516659 <nowiki>[2]</nowiki>]</sup>
** Terry Ligocki enumerated 30K more subtasks, increasing the number of holdouts to  '''775,799,715'''. A total of 250K subtasks out of the 1 million subtasks (or '''25%''') have been enumerated.<sup>[https://discord.com/channels/960643023006490684/1084047886494470185/1492652604088516659]</sup>


[[Category:This Month in Beaver Research|2026-05]]
[[Category:This Month in Beaver Research|2026-05]]

Latest revision as of 08:44, 10 May 2026

Prev: April 2026 This Month in Beaver Research Next: June 2026

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

General Recursive Functions:

  • Some new cryptids were hand-built:
    • Size 56, by Shawn on 2 May (simulating 5x+1 problem starting at 7).[1]
    • Size 49, by aparker, star and Shawn on 3 May (simulating Brocard's problem).[2]
  • The first non-trivial divergent GRF was found (size 15). It halts iff there exists some n ≥ 1 such that n+3 divides Tetr(n)=n(n+1)(n+2)6.[3] aparker[4] and star[5] proved that there is no such n.

Misc

Holdouts

  • BB(4,3)
    • Andrew Ducharme reduced the number of holdouts from 5,641,006 to 5,127,263, a 9.11% reduction, with mxdys's new inductive decider.[7]
  • BB(2,6)
    • Andrew Ducharme reduced the number of holdouts from 536,112 to 527,232 via Enumerate.py and TM-enum, a 1.66% reduction.[8][9]
    • Using the new inductive decider by mxdys and TM-enum, Andrew Ducharme first reduced the number of holdouts from 527,232 to 501,914[10][11], then to 439,120 again using the inductive decider.[12] In total this was a 16.71% reduction.
  • BB(2,7)
    • Terry Ligocki enumerated 30K more subtasks, increasing the number of holdouts to 775,799,715. A total of 250K subtasks out of the 1 million subtasks (or 25%) have been enumerated.[13]