TMBR: September 2025: Difference between revisions
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(Affine maps are Turing complete) |
(Updated the BB(7) and BB(2,6) sections of the Holdouts section. More to do.) |
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* [[BB(7)|BB(7):]] | * [[BB(7)|BB(7):]] | ||
** Andrew Ducharme has continued reducing [https://wiki.bbchallenge.org/wiki/BB(7)#Phase_2 the number of holdouts], from 59,727,905 to 28,189,617 (52.80% reduction) | ** Andrew Ducharme has continued reducing [https://wiki.bbchallenge.org/wiki/BB(7)#Phase_2 the number of holdouts], from 59,727,905 to 28,189,617 (52.80% reduction) | ||
** | ** Terry Ligocki is running an additional 41 filters/parameters. This reduced [https://wiki.bbchallenge.org/wiki/BB(7)#Phase_2 the number of holdouts], from 28,189,617 to 23,314,388 TMs (17.29% reduction) | ||
** The overall reduction this month was 72.9% | |||
* [[BB(2,6)|BB(2,6):]] | * [[BB(2,6)|BB(2,6):]] | ||
** Andrew Ducharme has continued reducing the number of holdouts from 18,054,938 to 17,629,828 (2.35% reduction). | ** Andrew Ducharme has continued reducing the number of holdouts from 18,054,938 to 17,629,828 (2.35% reduction). | ||
** Terry Ligocki [https://discord.com/channels/960643023006490684/1084047886494470185/1414681547444981944 shared that he ran 14 of @mxdys deciders on the holdouts list], reducing the [[BB(2,6)#Filtering|holdout count]] to a flattering 1,300,334 TMs (92.63% reduction). | ** Terry Ligocki [https://discord.com/channels/960643023006490684/1084047886494470185/1414681547444981944 shared that he ran 14 of @mxdys deciders on the holdouts list], reducing the [[BB(2,6)#Filtering|holdout count]] to a flattering 1,300,334 TMs (92.63% reduction). | ||
** @Peacemaker II discovered there were TMs missing from Andrew Ducharme's initial reductions. Andrew decided to scrap those reductions and run a single filter and reduced the holdout TMs from 22.3M to 20.4M (8.52% reduction). | ** @Peacemaker II discovered there were TMs missing from Andrew Ducharme's initial reductions. Andrew decided to scrap those reductions and run a single filter and reduced the holdout TMs from 22.3M to 20.4M (8.52% reduction). | ||
** Terry Ligocki then reran the 14 filters on the corrected holdouts and reduced the holdouts from 20.4M to 1.43M (92.9% reduction). This was followed by running 36 filters found examining a subset of the holdouts which reduced the holdouts from 1.43M to 970K (32.2% reduction). Overall the 50 filters reduced the holdouts by 95.23%. | ** Terry Ligocki then reran the 14 filters on the corrected holdouts and reduced the holdouts from 20.4M to 1.43M (92.9% reduction). This was followed by running 36 filters found examining a subset of the holdouts which reduced the holdouts from 1.43M to 970K (32.2% reduction). Overall, the 50 filters reduced the holdouts by 95.23%. | ||
** TODO: Andrew Ducharme is continuing to run filters and has gotten some more appreciable reductions. | ** TODO: Andrew Ducharme is continuing to run filters and has gotten some more appreciable reductions. | ||
** TODO: Make a clearly defined line that leads to the current 873,469 and a brief story of how this came about. | |||
*[[BB(4,3)|BB(4,3):]] | *[[BB(4,3)|BB(4,3):]] | ||
** TODO: Terry Ligocki is running a set of deciders/parameters from @mxdys' code to reduce the number of holdouts which are currently at ~461M TMs. Three passes have reduced the holdout count to ~96.7M TMs (an ~80% reduction). | ** TODO: Terry Ligocki is running a set of deciders/parameters from @mxdys' code to reduce the number of holdouts which are currently at ~461M TMs. Three passes have reduced the holdout count to ~96.7M TMs (an ~80% reduction). | ||
Revision as of 08:58, 27 September 2025
| Prev: August 2025 | This Month in Beaver Research | Next: October 2025 |
This Month in Beaver Research for September 2025.
TODO: BB(5) arXiv released https://arxiv.org/abs/2509.12337
TODO: BB(3,3) month.
In the News
- 14 Sep 2025. Ben Brubaker. Wired. The Quest to Find the Longest-Running Simple Computer Program.
- 17 Sep 2025. Hacker News. Determination of the fifth Busy Beaver value.
- 18 Sep 2025. Tuomas Kangasniemi. Tekniikkatalous. Iso matematiikan ongelma ratkesi 63 v jälkeen (Finnish) (English: A big math problem solved after 63 years).
Holdouts
- BB(6):
- Andrew Ducharme and @mxdys both found a family of 10 halting TMs independently, all halting in around steps.
- @mxdys decided two machines’ fates from the 50 Random Holdouts released in August, making 8/50 machined solved as of this month.
- Andrew Ducharme found a non-halting TM, to which Peacemaker II replied with another machine that turned out to be very similar, and non-halting as well. Later in his search Andrew found another non-halting TM.
- TODO: mxdys decided 776 holdouts using a new equivalence
- BB(7):
- Andrew Ducharme has continued reducing the number of holdouts, from 59,727,905 to 28,189,617 (52.80% reduction)
- Terry Ligocki is running an additional 41 filters/parameters. This reduced the number of holdouts, from 28,189,617 to 23,314,388 TMs (17.29% reduction)
- The overall reduction this month was 72.9%
- BB(2,6):
- Andrew Ducharme has continued reducing the number of holdouts from 18,054,938 to 17,629,828 (2.35% reduction).
- Terry Ligocki shared that he ran 14 of @mxdys deciders on the holdouts list, reducing the holdout count to a flattering 1,300,334 TMs (92.63% reduction).
- @Peacemaker II discovered there were TMs missing from Andrew Ducharme's initial reductions. Andrew decided to scrap those reductions and run a single filter and reduced the holdout TMs from 22.3M to 20.4M (8.52% reduction).
- Terry Ligocki then reran the 14 filters on the corrected holdouts and reduced the holdouts from 20.4M to 1.43M (92.9% reduction). This was followed by running 36 filters found examining a subset of the holdouts which reduced the holdouts from 1.43M to 970K (32.2% reduction). Overall, the 50 filters reduced the holdouts by 95.23%.
- TODO: Andrew Ducharme is continuing to run filters and has gotten some more appreciable reductions.
- TODO: Make a clearly defined line that leads to the current 873,469 and a brief story of how this came about.
- BB(4,3):
- TODO: Terry Ligocki is running a set of deciders/parameters from @mxdys' code to reduce the number of holdouts which are currently at ~461M TMs. Three passes have reduced the holdout count to ~96.7M TMs (an ~80% reduction).
- BB(3,4):
- TODO: @Xnoob545 and @Lúkos are working on the holdout list for BB(3,4), ~435M TMs, using @mxdys' deciders with various parameters.
BB Adjacent
- John Tromp announced on Discord that a 350-bit function now reaches the limit of BMS, an improvement from the previous 404 bits.
TODO: phrasing. Discord source: https://discord.com/channels/960643023006490684/1355653587824283678/1413637783045542038 and https://github.com/tromp/AIT/blob/master/fast_growing_and_conjectures/bms.lam
- TODO: savask shared "Busy Bug Game": https://discord.com/channels/960643023006490684/1362008236118511758/1415723582989930679
Blog Posts
- 12 Sep 2025. Katelyn Doucette. Bugs, Mazes, and the Unreasonably Effective Brady's Algorithm.
- 23 Sep 2025. Katelyn Doucette. Building the Busy Beaver Ladder.
Misc
- TODO: Affine maps are Turing complete and its relation to BMO1: https://discord.com/channels/960643023006490684/1239205785913790465/1420457986564030641 https://discord.com/channels/960643023006490684/1239205785913790465/1420491357969059910