BB(2,4) - Revision history

Polygon: Added Category:BB(2,4)

2026-07-06T19:21:27Z

Added Category:BB(2,4)

← Older revision		Revision as of 19:21, 6 July 2026
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	<references/>		<references/>
	[[Category:BB Domains]]		[[Category:BB Domains]]
			[[Category:BB(2,4)]]

Polygon: Fixed link to "Champions"

2025-08-11T11:04:01Z

Fixed link to "Champions"

← Older revision		Revision as of 11:04, 11 August 2025
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	== Champion ==		== Champion ==
	S(2,4) = 3,932,964 and Σ(2,4) = 2050 and both are achieved by only one [[~~Champion~~#4-Symbol TMs\|champion]] (in [[TNF]]):		S(2,4) = 3,932,964 and Σ(2,4) = 2050 and both are achieved by only one [[Champions#4-Symbol TMs\|champion]] (in [[TNF]]):
	* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}		* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}

Polygon: Linked champion to corresponding section

2025-08-11T10:42:39Z

Linked champion to corresponding section

← Older revision		Revision as of 10:42, 11 August 2025
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	== Champion ==		== Champion ==
	S(2,4) = 3,932,964 and Σ(2,4) = 2050 and both are achieved by only one [[champion]] (in [[TNF]]):		S(2,4) = 3,932,964 and Σ(2,4) = 2050 and both are achieved by only one [[Champion#4-Symbol TMs\|champion]] (in [[TNF]]):
	* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}		* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}

Polygon: Used new redirect to "Champions"

2025-08-11T10:31:43Z

Used new redirect to "Champions"

← Older revision		Revision as of 10:31, 11 August 2025
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	== Champion ==		== Champion ==
	S(2,4) = 3,932,964 and Σ(2,4) = 2050 and both are achieved by only one [[~~Champions\|~~champion]] (in [[TNF]]):		S(2,4) = 3,932,964 and Σ(2,4) = 2050 and both are achieved by only one [[champion]] (in [[TNF]]):
	* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}		* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}

Polygon: Added link to "champions"

2025-08-11T10:24:35Z

Added link to "champions"

← Older revision		Revision as of 10:24, 11 August 2025
Line 8:		Line 8:

	== Champion ==		== Champion ==
	S(2,4) = 3,932,964 and Σ(2,4) = 2050 and both are achieved by only one champion (in [[TNF]]):		S(2,4) = 3,932,964 and Σ(2,4) = 2050 and both are achieved by only one [[Champions\|champion]] (in [[TNF]]):
	* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}		* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}

Polygon: Prepare Category move of BB-domains

2025-08-10T23:42:21Z

Prepare Category move of BB-domains

← Older revision		Revision as of 23:42, 10 August 2025
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	== References ==		== References ==
	<references/>		<references/>
	[[Category:BB ~~Domain~~]]		[[Category:BB Domains]]

Fr tho: more specific date

2025-06-25T00:34:37Z

more specific date

← Older revision		Revision as of 00:34, 25 June 2025
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	The 2-state, 4-symbol Busy Beaver problem, '''BB(2,4)''', obtained a lower bound of BB(2,4) ≥ 3,932,964 when the winner was found in 2005.		The 2-state, 4-symbol Busy Beaver problem, '''BB(2,4)''', obtained a lower bound of BB(2,4) ≥ 3,932,964 when the winner was found in February 2005.

	On August 22, 2024, BB(2,4) = 3,932,964 was officially confirmed by the [[bbchallenge.org]] massively collaborative research project, when a proof for the BB(2,4) case was added to [[Coq-BB5]] and successfully compiled.		On August 22, 2024, BB(2,4) = 3,932,964 was officially confirmed by the [[bbchallenge.org]] massively collaborative research project, when a proof for the BB(2,4) case was added to [[Coq-BB5]] and successfully compiled.

Fr tho: better description

2025-05-17T11:56:04Z

better description

← Older revision		Revision as of 11:56, 17 May 2025
Line 1:		Line 1:
	The 2-state, 4-symbol Busy Beaver problem, '''BB(2,4)''', obtained a lower bound of BB(2,4) ≥ 3,932,964 when the winner was found in 2005.		The 2-state, 4-symbol Busy Beaver problem, '''BB(2,4)''', obtained a lower bound of BB(2,4) ≥ 3,932,964 when the winner was found in 2005.

	On August 22, 2024, BB(2,4) = 3,932,964 was officially confirmed by the bbchallenge project, when a proof for the BB(2,4) case was added to [[Coq-BB5]] and successfully compiled.		On August 22, 2024, BB(2,4) = 3,932,964 was officially confirmed by the [[bbchallenge.org]] massively collaborative research project, when a proof for the BB(2,4) case was added to [[Coq-BB5]] and successfully compiled.

	== History ==		== History ==

Fr tho: Improved introduction

2025-05-17T11:52:38Z

Improved introduction

← Older revision		Revision as of 11:52, 17 May 2025
Line 1:		Line 1:
	The 2-state, 4-symbol Busy Beaver problem, '''BB(2,4)''', ~~was officially found to be~~ 3,932,964 on August 22, 2024 by the bbchallenge project, when a proof for the BB(2,4) case was added to [[Coq-BB5]] and successfully compiled~~. The champion machine M, has S(M) = 3,932,964 and Σ(M) = 2,050~~.		The 2-state, 4-symbol Busy Beaver problem, '''BB(2,4)''', obtained a lower bound of BB(2,4) ≥ 3,932,964 when the winner was found in 2005.

			On August 22, 2024, BB(2,4) = 3,932,964 was officially confirmed by the bbchallenge project, when a proof for the BB(2,4) case was added to [[Coq-BB5]] and successfully compiled.

	== History ==		== History ==

Fr tho: Update halters section and introduction for consistency

2025-05-17T11:41:32Z

Update halters section and introduction for consistency

← Older revision		Revision as of 11:41, 17 May 2025
Line 1:		Line 1:
	BB(2,4) was officially found to be 3,932,964 on August 22, 2024 by the bbchallenge project, when a proof for the BB(2,4) case was added to [[Coq-BB5]] and successfully compiled. The champion machine M, has S(M) = 3,932,964 and Σ(M) = 2,050.		The 2-state, 4-symbol Busy Beaver problem, '''BB(2,4)''', was officially found to be 3,932,964 on August 22, 2024 by the bbchallenge project, when a proof for the BB(2,4) case was added to [[Coq-BB5]] and successfully compiled. The champion machine M, has S(M) = 3,932,964 and Σ(M) = 2,050.

	== History ==		== History ==
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	* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}		* {{TM\|1RB2LA1RA1RA_1LB1LA3RB1RZ\|halt}}

	== ~~Enumeration~~ ==		== Top Halters ==
	The top 20 longest running BB(2,4) TMs (in [[TNF-1RB]]) are:		The top 20 longest running BB(2,4) TMs (in [[TNF-1RB]]) are:
	Standard Format Steps Σ		<pre>
	1RB2LA1RA1RA_1LB1LA3RB1RZ 3932964 2050		Standard Format Status Steps Σ
	1RB3LA1LA1RA_2LA1RZ3RA3RB ~~7195~~ 90		1RB2LA1RA1RA_1LB1LA3RB1RZ Halt 3932964 2050
	1RB3LA1LA1RA_2LA1RZ3LA3RB ~~6445~~ 84		1RB3LA1LA1RA_2LA1RZ3RA3RB Halt 7195 90
	1RB3LA1LA1RA_2LA1RZ2RA3RB ~~6445~~ 84		1RB3LA1LA1RA_2LA1RZ3LA3RB Halt 6445 84
	1RB2RB3LA2RA_1LA3RB1RZ1LB ~~2351~~ 60		1RB3LA1LA1RA_2LA1RZ2RA3RB Halt 6445 84
	1RB3RA1LA2RB_2LA3LA1RZ1RA ~~1021~~ 53		1RB2RB3LA2RA_1LA3RB1RZ1LB Halt 2351 60
	1RB3LA1RZ0RB_2LB2LA0LA0RA ~~1001~~ 26		1RB3RA1LA2RB_2LA3LA1RZ1RA Halt 1021 53
	1RB2LA1RZ3LA_2LA2RB3RB2LB ~~770~~ 30		1RB3LA1RZ0RB_2LB2LA0LA0RA Halt 1001 26
	1RB2LB1RZ3LA_2LA2RB3RB2LB ~~708~~ 29		1RB2LA1RZ3LA_2LA2RB3RB2LB Halt 770 30
	1RB2LA0RB1LB_1LA3RA1RA1RZ ~~592~~ 24		1RB2LB1RZ3LA_2LA2RB3RB2LB Halt 708 29
	1RB3LA3RA0LA_2LB1LA1RZ2RA ~~392~~ 20		1RB2LA0RB1LB_1LA3RA1RA1RZ Halt 592 24
	1RB3LA1LA1RA_2LA1RZ2RB3RB ~~376~~ 21		1RB3LA3RA0LA_2LB1LA1RZ2RA Halt 392 20
	1RB3LA1LA1RA_2LA1RZ0LA3RB ~~376~~ 21		1RB3LA1LA1RA_2LA1RZ2RB3RB Halt 376 21
	1RB3LA3RB0LA_2LA1RZ1LB3RA ~~374~~ 22		1RB3LA1LA1RA_2LA1RZ0LA3RB Halt 376 21
	1RB1RA1LB0RA_2LA3RB2RA1RZ ~~335~~ 18		1RB3LA3RB0LA_2LA1RZ1LB3RA Halt 374 22
	1RB2LA3LA1LB_2LA1RZ2RB0RA ~~292~~ 18		1RB1RA1LB0RA_2LA3RB2RA1RZ Halt 335 18
	1RB0RB1RZ0LA_2LA3RA3LA1LB ~~289~~ 13		1RB2LA3LA1LB_2LA1RZ2RB0RA Halt 292 18
	1RB1LA1RZ0LB_2LA3RB1RB2RA ~~283~~ 18		1RB0RB1RZ0LA_2LA3RA3LA1LB Halt 289 13
	1RB3LA3RA0LA_2LB1LA1RZ3RA ~~266~~ 19		1RB1LA1RZ0LB_2LA3RB1RB2RA Halt 283 18
	1RB2RB1RZ1LB_2LA2LB3RB0RB ~~241~~ 15		1RB3LA3RA0LA_2LB1LA1RZ3RA Halt 266 19
			1RB2RB1RZ1LB_2LA2LB3RB0RB Halt 241 15
			</pre>

	For the top 100 halting BB(2,4) TMs, see: https://github.com/sligocki/busy-beaver/blob/main/Machines/bb/2x4.txt		For the top 100 halting BB(2,4) TMs, see: https://github.com/sligocki/busy-beaver/blob/main/Machines/bb/2x4.txt