BB(2,5): Difference between revisions
Jump to navigation
Jump to search
(May read as a single link "Cryptid Hydra") |
(Add comment about lower bound) |
||
| Line 1: | Line 1: | ||
The 2-state, 5-symbol Busy Beaver problem '''BB(2,5)''' is unsolved. With the discovery of the [[Cryptids|Cryptid]] machine [[Hydra]] by Daniel Yuan in April 2024, we now know that we must solve a [[Collatz-like]] problem in order to solve BB(2,5) and thus [https://www.sligocki.com/2024/05/10/bb-2-5-is-hard.html BB(2,5) is Hard]. | The 2-state, 5-symbol Busy Beaver problem '''BB(2,5)''' is unsolved. With the discovery of the [[Cryptids|Cryptid]] machine [[Hydra]] by Daniel Yuan in April 2024, we now know that we must solve a [[Collatz-like]] problem in order to solve BB(2,5) and thus [https://www.sligocki.com/2024/05/10/bb-2-5-is-hard.html BB(2,5) is Hard]. | ||
The current BB(2,5) champion is {{TM|1RB3LA4RB0RB2LA_1LB2LA3LA1RA1RZ|halt}}, also discovered by Daniel Yuan in June 2024. It is notable for being the only champion machine that exhibits [[Counter]] behavior. | The current BB(2,5) champion is {{TM|1RB3LA4RB0RB2LA_1LB2LA3LA1RA1RZ|halt}}, also discovered by Daniel Yuan in June 2024. It is notable for being the only champion machine that exhibits [[Counter]] behavior. It provides the lower bound: | ||
<math display="block">S(2,5) > \Sigma(2,5) > 10^{10^{10^{3\,314\,360}}} > 10 \uparrow\uparrow 4</math> | |||
Revision as of 22:14, 4 February 2025
The 2-state, 5-symbol Busy Beaver problem BB(2,5) is unsolved. With the discovery of the Cryptid machine Hydra by Daniel Yuan in April 2024, we now know that we must solve a Collatz-like problem in order to solve BB(2,5) and thus BB(2,5) is Hard.
The current BB(2,5) champion is 1RB3LA4RB0RB2LA_1LB2LA3LA1RA1RZ (bbch), also discovered by Daniel Yuan in June 2024. It is notable for being the only champion machine that exhibits Counter behavior. It provides the lower bound:
