TMBR: December 2025

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This Month in Beaver Research

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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 Year in Beaver Research _{(TYBR - "Thank You Beaver Researchers!")}

Holdouts Reductions.

• BB(6) - Reduced from 3571 to 1416 holdouts. Hence, 2155 machines were solved this year. This is a 60% reduction.
• BB(7) - Enumeration was completed, the number of holdouts was reduced from an initial 85,853,789 to 20,405,295 machines, a 76.23% reduction.
• BB(4,3) - Reduced from 460,916,384 to 9,401,447 holdouts, a 97.96% reduction.
• BB(3,4) - Reduced from 434,787,751 to 15,136,283 holdouts, a 96.52% reduction.
• BB(2,5) - Reduced from 217 to 75, a 65.43% reduction.
• BB(2,7) - Enumeration started, 50K of the 1M subtasks have been enumerated (5%).

New Methods.

TODO

Meta.

TODO

BB Adjacent.

TODO

BB Adjacent

TODO. Register machines, General Recursive Functions.

Holdouts

• BB(6):
  • There are 14 holdouts left to simulate up to 1e12 steps, and 312 to simulate up to 1e13 steps^[1]. The two lists can be found here.
• BB(3,4):
  • TODO: Phase 2 stage 8.
• BB(2,7):
  • Terry Ligocki enumerated 10K more subtasks, increasing the number of holdouts to 150,662,006 and making 50K of the 1 million subtasks enumerated. (5/100)