Instruction-Limited Busy Beaver: Revision history

26 July 2025

• curprev 23:1923:19, 26 July 2025‎ MrBrain talk contribs‎ 7,652 bytes +26‎ Added an example lower bound to illustrate the likely true size of BBi(8) in the explanatory note below the BBi table. Tag: Visual edit
• curprev 23:0323:03, 26 July 2025‎ MrBrain talk contribs‎ 7,626 bytes +335‎ Clarified that the current value for BBi(n) is a lower bound based on the currently known estimate for Σi(8), the number of symbols written to tape. Tag: Visual edit
• curprev 21:4321:43, 26 July 2025‎ MrBrain talk contribs‎ 7,291 bytes 0‎ Clarifying description of the current BBi(8) champion, making clear it is not a current BB(3,4) champion. Tag: Visual edit
• curprev 21:1821:18, 26 July 2025‎ MrBrain talk contribs‎ 7,291 bytes +92‎ Link to bbchallenge discord of machine announcement.
• curprev 21:1621:16, 26 July 2025‎ MrBrain talk contribs‎ 7,199 bytes −8‎ Updated description of new current BBi(8) champion. Tag: Visual edit
• curprev 21:1421:14, 26 July 2025‎ MrBrain talk contribs‎ 7,207 bytes +9‎ Edited the code for the current champion BBi(8) TM.
• curprev 21:1221:12, 26 July 2025‎ MrBrain talk contribs‎ 7,198 bytes 0‎ Number of steps found by Nick for new current BBi(8) champion. Tag: Visual edit
• curprev 19:2119:21, 26 July 2025‎ Qwerpiw talk contribs‎ 7,198 bytes +24‎ No edit summary
• curprev 17:5717:57, 26 July 2025‎ MrBrain talk contribs‎ 7,174 bytes 0‎ Corrected total number of TNF machines for n<=8. Tag: Visual edit

25 July 2025

• curprev 22:2422:24, 25 July 2025‎ MrBrain talk contribs‎ m 7,174 bytes 0‎ Minor wording change in Motivation section. Tag: Visual edit
• curprev 22:1922:19, 25 July 2025‎ MrBrain talk contribs‎ 7,174 bytes 0‎ Fixed equation for m-symbol steps sequence. Tag: Visual edit
• curprev 22:0922:09, 25 July 2025‎ MrBrain talk contribs‎ m 7,174 bytes +12‎ Slight wording change in Motivation section. Tag: Visual edit
• curprev 21:0721:07, 25 July 2025‎ MrBrain talk contribs‎ m 7,162 bytes −16‎ Cleaning up some wording in "motivation" section. Tag: Visual edit
• curprev 21:0021:00, 25 July 2025‎ MrBrain talk contribs‎ m 7,178 bytes +10‎ Clarified the primary motivation of BBi. Tag: Visual edit
• curprev 20:4920:49, 25 July 2025‎ MrBrain talk contribs‎ 7,168 bytes +36‎ Added a new "Motivation" section in the previous edit. Reintroduced some formatting that I had in an offline document while composing this section. Tag: Visual edit
• curprev 20:4220:42, 25 July 2025‎ MrBrain talk contribs‎ 7,132 bytes +2,498‎ No edit summary Tag: Visual edit: Switched
• curprev 15:1015:10, 25 July 2025‎ Sligocki talk contribs‎ 4,634 bytes +114‎ Rework the BBi requires solving BB section Tag: Visual edit
• curprev 13:0013:00, 25 July 2025‎ MrBrain talk contribs‎ 4,520 bytes −2‎ A halting instruction is an instruction. BB(4,2) has eight instructions, not 7. Tag: Visual edit
• curprev 04:0204:02, 25 July 2025‎ ADucharme talk contribs‎ m 4,522 bytes +21‎ made bound look prettier Tag: Visual edit
• curprev 04:0004:00, 25 July 2025‎ ADucharme talk contribs‎ 4,501 bytes +32‎ →‎Champions: changing edits on subsumed BB domains to get closer to my original intent Tag: Visual edit
• curprev 03:4603:46, 25 July 2025‎ ADucharme talk contribs‎ 4,469 bytes +32‎ made space for upper bound on instructions for BB(n,m), since it does exist and is used later in the article, within the current text Tag: Visual edit
• curprev 00:0100:01, 25 July 2025‎ MrBrain talk contribs‎ m 4,437 bytes +4‎ Added the remaining "-1" to terms in which it had been omitted. Tag: Visual edit

24 July 2025

• curprev 23:5723:57, 24 July 2025‎ MrBrain talk contribs‎ m 4,433 bytes +2‎ Expanded BB(n) to BB(n,2) to avoid confusion. Tag: Visual edit
• curprev 23:5623:56, 24 July 2025‎ MrBrain talk contribs‎ 4,431 bytes +13‎ Modified the equations describing the limits of BBi(2n-1) in relation to BB(2,n) and BB(n,2). BBi(2n-1) is not necessarily as high as BB(2,n) if that BB is the basis for the optimal BBi configuration, since BBi does not include the final halting instruction, where as traditional BB does. Tag: Visual edit
• curprev 19:1519:15, 24 July 2025‎ Sligocki talk contribs‎ m 4,418 bytes +101‎ Formatting
• curprev 17:2417:24, 24 July 2025‎ MrBrain talk contribs‎ 4,317 bytes 0‎ Corrected TNF size for n=8. Tag: Visual edit
• curprev 17:2017:20, 24 July 2025‎ MrBrain talk contribs‎ 4,317 bytes +115‎ Added a new row for n=8. Formatting is not the same as the previous rows, so we can fix that next. Tag: Visual edit
• curprev 16:5116:51, 24 July 2025‎ Sligocki talk contribs‎ 4,202 bytes −42‎ Reword BB as not instruction limited Tag: Visual edit
• curprev 15:5615:56, 24 July 2025‎ Sligocki talk contribs‎ m 4,244 bytes 0‎ Update name Tag: Visual edit
• curprev 15:5215:52, 24 July 2025‎ Sligocki talk contribs‎ m 4,244 bytes 0‎ Sligocki moved page Limited Instruction Busy Beaver to Instruction-Limited Busy Beaver: MrBrain suggested this preference since it puts the key word "Instruction" first

23 July 2025

• curprev 06:0506:05, 23 July 2025‎ ADucharme talk contribs‎ 4,244 bytes +269‎ more connections between BB and BBi Tag: Visual edit
• curprev 05:5205:52, 23 July 2025‎ ADucharme talk contribs‎ m 3,975 bytes +2‎ off by one error corrected Tag: Visual edit
• curprev 04:4104:41, 23 July 2025‎ Sligocki talk contribs‎ m 3,973 bytes +41‎ →‎Champions Tag: Visual edit
• curprev 04:2304:23, 23 July 2025‎ Int-y1 talk contribs‎ 3,932 bytes +111‎ link BBi(8) to BB(3,3)
• curprev 03:0203:02, 23 July 2025‎ Sligocki talk contribs‎ 3,821 bytes −3‎ →‎Champions: BBi(7) champ proven Tag: Visual edit

22 July 2025

• curprev 19:5219:52, 22 July 2025‎ ADucharme talk contribs‎ m 3,824 bytes +1‎ →‎Champions Tag: Visual edit
• curprev 19:4919:49, 22 July 2025‎ ADucharme talk contribs‎ 3,823 bytes +357‎ lame lower bound for BBi(n) Tag: Visual edit
• curprev 19:2419:24, 22 July 2025‎ ADucharme talk contribs‎ 3,466 bytes −3‎ mathematical language change Tag: Visual edit
• curprev 19:1519:15, 22 July 2025‎ Sligocki talk contribs‎ m 3,469 bytes +630‎ →‎Champions: Align numbers in table.
• curprev 19:0719:07, 22 July 2025‎ ADucharme talk contribs‎ 2,839 bytes −52‎ language edits Tag: Visual edit

19 July 2025

• curprev 20:3520:35, 19 July 2025‎ MrBrain talk contribs‎ 2,891 bytes +164‎ Added the definition of Σi(n), the non-blank symbols function for n-instruction TMs. Tag: Visual edit
• curprev 20:2520:25, 19 July 2025‎ MrBrain talk contribs‎ 2,727 bytes +10‎ Clarified that we are replacing an undefined transition in a BBi TM with a halting instruction in the equivalent BB TM. Tag: Visual edit
• curprev 20:2220:22, 19 July 2025‎ MrBrain talk contribs‎ 2,717 bytes +182‎ Modified the section describing a key difference between TMs in the BBi contest and the BB contests. In BBi, halting on an undefined transition is an advantage, because it saves us having to add an explicit halting instruction. In traditional BB, this is would be a disadvantage, because we could simply replace the undefined transition with a halting instruction, which allows the TM to take an additional step. Tag: Visual edit

18 July 2025

• curprev 03:5803:58, 18 July 2025‎ Sligocki talk contribs‎ 2,535 bytes +1‎ Add 0RB BBi(1) champ. Tag: Visual edit: Switched

17 July 2025

• curprev 06:3706:37, 17 July 2025‎ MrBrain talk contribs‎ 2,534 bytes +11‎ Added cumulative TNF value for all machines having 7 or fewer states. Tag: Visual edit
• curprev 06:0006:00, 17 July 2025‎ Sligocki talk contribs‎ m 2,523 bytes +1‎ →‎Champions
• curprev 05:5905:59, 17 July 2025‎ Sligocki talk contribs‎ 2,522 bytes +171‎ →‎Champions: Add BBi(7) co-champion Tag: Visual edit
• curprev 02:1502:15, 17 July 2025‎ Sligocki talk contribs‎ m 2,351 bytes +100‎ →‎Champions Tag: Visual edit

16 July 2025

• curprev 23:3723:37, 16 July 2025‎ Sligocki talk contribs‎ 2,251 bytes +1,378‎ Add table of champions Tag: Visual edit
• curprev 21:4721:47, 16 July 2025‎ Sligocki talk contribs‎ 873 bytes +873‎ Created page with "An '''n-instruction Turing machine''' is a Turing machine with an arbitrary number of states and symbols, but limited to only ''n'' defined transitions/instructions in its transition table (all others are undefined). The '''Limited Instruction Busy Beaver''' (BBi(n)) problem is the Busy Beaver problem limited to n-instruction TMs. So BBi(n) is the longest runtime for all halting n-instruction TMs when started on a blank tape. A TM is considered to halt as soon as it..."