BB(6) hunt
Machines / #18

1RB1RF_1RC0RA_1LD1RE_1LE0LE_0RA0LD_0RB---

#18ParkedBell eats counterbbchallenge ↗Explorer

Where it stands

Parked at the deeper analysis

Funded stage prove_margin (2026-10-10) ended by its exit rule: failed bound -> parked, cryptid-margin suspect. Fast exact phase map (1321/1321 logged starts, 40/40 direct one-phase checks) extends the orbit to phase 11798, M=114,554 (~9.7e13 steps): no halt, margin k_align <= M-1 at every start, max ratio 0.467, no drift toward 1.

Read the full status

But the margin is not provable from counter structure: random reachable-looking counters (aligned, digits 1, random or orbit widths) break it in 7/200 and 4/200 runs (up to 2.84x), and it depends on the exact bell: orbit phase 10666 with bell 102,051 instead of 102,052 gives next ratio 0.979 (orbit: 0). No tested break led to halting (0/400), so not flagged CRYPTID_CANDIDATE. Rules (J-rule, Gap-Inc, J-crossing, walk), G1 and the fast map remain valid for any later attempt.

Observe
Deepen
Informal proof
Rocq
space-time diagram, first 10,000 steps from blank
The first 10,000 steps from a blank tape. Time runs down; white is 1.
About this picture

The standard picture (bbchallenge.org's Default view): each row is the whole tape at one step, time runs downward, and the head's path draws the pattern.

bbchallenge-defaultStart blankRows steps 0 → 10,000, top to bottomWindow cells −200..199, left to rightColors 1 0 or unvisited

Overview

In one sentence

BMO7-like bell + walking marker; counter is base 3, not binary; the eat step rebuilds it irregularly

Status
Parkedfunded:prove margin · updated 2026-10-10Not blocking · Stuck at the funded:prove margin stage. Answer Q1–Q3 whenever; a “no” redirects the work.
idle since Oct 10 13:25 · status.json 2026-10-10
Class
Bell eats counterours: Bell eats counter (sheet) · ours adds: BMO 7 layout, but a base-3 counter · med confidence
On the list
line 314 of BB6_holdouts_663.txt · historical 740 line 347
#18eqv ×1sim 1e15
Your calls on file 2
funded
option: prove_margin · date: 2026-10-10
2026-10-10 · prove_margin
Non-halting of #18 now reduces to the margin M-1 >= k_align(C) at every phase start. Fund one stage to prove it, or park #18 as a cryptid-margin case? (Dennis: go with all recommendations (2026-10-10))

Mechanism

How it works: 3 notes
  • Tape = a long 10-sea (the bell) + a short counter at its right end; a marker walks right through the bell.
  • Each bounce adds 1 to the base-3 counter: a digit = a wall at offset 1/2/3 in its frame; overflow appends a digit.
  • When the marker hits the counter, the bell eats its low end (grows by g >= 2); g and the new counter depend only on it.

Figures for Checkpoint A

Fig 1 · One phase: entries into state CQ1

One row per entry into C, every 2nd cell. Look at the black/white diagonal and the right-edge strip.

One phase: entries into state C
bbchallenge-defaultStart mid-run: step 2,097,352Rows entries into state CWindow cells -48..544, 1 px = 2 cellsColors 1 0 head
Start: a phase start: left record, head at cell -48 · Rows: 563 rows, steps 2,097,352..2,255,952; the next phase starts at 2,255,931 · Window: only every 2nd cell is drawn (-48, -46, ..., 544) · Colors: red: it enters C moving right; Because only every 2nd cell is drawn, the bell (10)^M looks solid white where its 1s fall on drawn cells and solid black where the marker has shifted it by one cell: the white/black diagonal is the marker
Fig 2 · Counter from zero, from a built tapeQ2

From a built tape, counter at 0. Look at the staircase on the right and the pattern within it.

Counter from zero, from a built tape
bbchallenge-defaultStart constructed: 0∞ A> (10)100 00101001 0∞Rows entries into state CWindow cells 197..224, 1 px = 0.2 cellsColors 1 0 or never visited head
Start: bell of 100 blocks, then the counter X(0) = 00101001 = value 0 · Rows: 178 rows, steps 0..21,000 · Window: each cell is 5x5 px; bell = cells 0..199, counter from cell 200 · Colors: red: it enters C moving right
Fig 3 · Counter at every phase start, to 1 billionQ3

Right edge pinned; one row per phase start, to 1e9. Compare the counter strip from row to row.

Counter at every phase start, to 1 billion
bbchallenge-defaultStart blankRows left recordsWindow cells -109..0, 1 px = 0.33 cellsColors 1 0 or never visited head
Rows: the start, then one row per new leftmost cell = one row per phase start (313 rows, steps 0..1,000,000,000; rows are not equal time) · Window: (each cell is 3x3 px), counted from the right edge (each row is shifted so its rightmost visited cell is at 0) · Colors: green: at the left edge, just moved left
More figures (2)Fig 4–5: Edge records to 100 million steps · Blaze view, 100 million steps
Fig 4 · Edge records to 100 million stepsviewer ↗

The bell grows; the counter rides its right edge.

Edge records to 100 million steps
bbchallenge-defaultStart blankRows left/right recordsWindow cells -154..1903, 1 px = 1 cellColors 1 0 or never visited head just moved right/left
Rows: the start, then one row each time the head reaches a new leftmost or rightmost cell (2,058 rows, steps 0..100,000,000; rows are not equal time)
Fig 5 · Blaze view, 100 million stepsviewer ↗

The bell (half 1s) averages to pale orange; growth ~ t^0.34.

Blaze view, 100 million steps
bbchallenge-blazeStart blankRows Blaze time blocks of 131,072 stepsWindow cells -154..1903, 1 px = 2.57 cellsColors 0 1 mixed
Rows: (averaged), 763 blocks stretched to 500 px, so 1 px row ~ 200,000 steps (steps 0..100,000,000) · Colors: paler orange: each pixel averages its cells over its time block; no head drawn; the bell (10)^M is half 1s, so it averages to pale orange
Rules (8/8 validated)exact tape rewrites the proof will formalize, each re-checked by simulation
rulefrom ⟶ tocasesstepschecked
sweep-in
A> (10)n
⟶ 10 (01)n-1 B>
n>=12n✓60/60
sweep-R
B> (10)n
⟶ (01)n B>
n>=02n✓60/60
sweep-L
(10)n <D
⟶ <D (01)n
n>=02n✓60/60
shift-A
A> (01)n
⟶ (10)n A>
n>=0 (used inside the counter)2n✓60/60
Inc (one bounce, X form)
0∞ (10)a A> (10)b+1 X(v) 0∞
⟶ 0∞ (10)a+1 A> (10)b X(v+1) 0∞
b>=1. X(v) = D(v mod 3) 1 T(v div 3) 001; D = 0010|0110|0100; T = bijective base-3 digits LSB first, 1/2/3 = 0001/0011/0010—✓450/450
Inc (one bounce, any frames)
0∞ (10)a A> (10)b+1 F 0∞
⟶ 0∞ (10)a+1 A> (10)b inc(F) 0∞
b>=1. F = frames (d_i in 1..3, even width w_i>=4), wall gaps 1,d_0,w_0-d_0,...; inc = base 3 on d (3->1 carries), overflow appends (1,4); widths unchanged—✓400/400
Phase (M-1 bounces)
0∞ A> (10)M X(v) 0∞
⟶ 0∞ (10)M-1 A> 10 X(v+M-1) 0∞
M>=2; Inc applied M-1 times—✓40/40
Eat (bell meets counter)
0∞ (10)N A> 10 F 0∞
⟶ 0∞ <E (10)N+g(F) F' 0∞
g and F' depend on F only (N vs N+k, 60/60). Examples: [(1,6)]->+7,[(1,6)]; [(3,6)]->+2,[(1,10),(1,6)]; [(1,10)]->+7,[(1,4),(1,6)]. Closed form: OPEN—✓60/60
Compressed historythe tape as 0∞ A> (10)M W 0∞ at 39 moments: where the rules are read off
0∞ A> (10)M W 0∞
stepM = bell blocks at phase start|W| = counter cellsW as wall gaps (o = 00 hole, # = 11 bump)
41281o 1o 5o
64371o 1o 1o 3o
163771o 1o 1o 3o
3628131o 1o 1o 3o 2# 4o
6699191o 1o 11o 1o 1o 3o
1,10410251o 1o 11o 1o 1o 3o 2# 4o
1,67517191o 1o 11o 1o 1o 3o
2,57418251o 1o 1o 9o 1o 5o 2# 4o
10,06733501o 1o 41o 1o 5o
128,733111191o 1o 1o 3o 3o 1o 2# 2o 3o 1o
529,171172291o 1o 13o 1o 1o 5o 3o 3o
1,428,457241311o 1o 11o 1o 1o 1o 3o 5o 3o 3o
2,974,083326171o 1o 5o 2# 1# 2o 3o 1o
5,636,701388331o 1o 11o 1o 5o 1o 1o 5o 3o 3o
9,167,327444411o 1o 25o 1o 1o 5o 3o 3o
13,840,601520171o 1o 1o 3o 3o 3o 1o 3o
19,709,255559671o 1o 27o 1o 19o 1o 1o 5o 3o 3o 2# 2o
27,284,505666161o 1o 3o 1o 3o 1o 5o
36,981,311718611o 1o 33o 1o 5o 1o 1o 3o 2# 4o 2# 2o 2# 2o
48,739,545799501o 1o 27o 1o 13o 1o 5o
62,765,319871231o 1o 1o 3o 1o 5o 2# 4o 3o 1o
79,028,529928491o 1o 25o 1o 9o 1o 1o 1o 2# 2o 3o 1o
97,840,9391,002401o 1o 17o 1o 5o 1o 7o 1o 5o
119,322,1971,083311o 1o 13o 1o 1o 1o 2# 2o 1o 3o 1o 3o
144,732,3111,168451o 1o 21o 1o 5o 1o 1o 1o 2# 2o 1o 3o 1o 3o
174,085,2651,252521o 1o 9o 1o 11o 1o 5o 1o 3o 1o 11o 1o 5o
207,484,4351,326491o 1o 15o 1o 5o 1o 5o 1o 1o 3o 2# 4o 2# 2o 1o 3o
244,435,8331,401311o 1o 1o 3o 1o 3o 2# 2o 3o 1o 1o 3o 2# 2o 1o 3o
285,517,7991,469511o 1o 1o 3o 3o 19o 2# 6o 3o 3o 2# 2o 1o 3o
331,301,6331,556371o 1o 1o 3o 3o 3o 3o 3o 3o 3o 3o 1o 2# 2o 1o 3o
382,417,7311,642411o 1o 5o 1o 5o 1o 9o 1o 1o 3o 2# 2o 3o 1o 1o 3o
438,884,1211,705711o 1o 41o 1o 13o 1o 1o 5o 3o 3o
501,203,3951,791551o 1o 5o 1o 19o 1o 5o 1o 1o 1o 2# 2o 2# 6o 3o 3o
568,808,3451,887311o 1o 1o 1o 2# 10o 1o 5o 1o 3o 2# 2o
643,095,9031,957511o 1o 17o 1o 1o 3o 1o 5o 1o 5o 2# 4o 1o 3o 2# 2o
723,172,2812,025751o 1o 27o 1o 27o 1o 1o 3o 2# 2o 2# 2o 2# 2o
809,229,4952,106691o 1o 1o 11o 3o 19o 3o 11o 3o 3o 1o 3o 2# 2o 2# 2o
902,342,0532,188571o 1o 17o 1o 1o 3o 3o 5o 1o 5o 1o 7o 3o 3o 2# 2o
991,609,3602,263471o 1o 5o 1o 1o 3o 1o 15o 3o 1o 1o 5o 3o 1o 2# 2o
M = bell blocks at phase startlast 2,263
2,2632419.9e8log xstep 41: M = bell blocks at phase start = 2step 64: M = bell blocks at phase start = 3step 163: M = bell blocks at phase start = 7step 362: M = bell blocks at phase start = 8step 669: M = bell blocks at phase start = 9step 1104: M = bell blocks at phase start = 10step 1675: M = bell blocks at phase start = 17step 2574: M = bell blocks at phase start = 18step 10067: M = bell blocks at phase start = 33step 128733: M = bell blocks at phase start = 111step 529171: M = bell blocks at phase start = 172step 1428457: M = bell blocks at phase start = 241step 2974083: M = bell blocks at phase start = 326step 5636701: M = bell blocks at phase start = 388step 9167327: M = bell blocks at phase start = 444step 13840601: M = bell blocks at phase start = 520step 19709255: M = bell blocks at phase start = 559step 27284505: M = bell blocks at phase start = 666step 36981311: M = bell blocks at phase start = 718step 48739545: M = bell blocks at phase start = 799step 62765319: M = bell blocks at phase start = 871step 79028529: M = bell blocks at phase start = 928step 97840939: M = bell blocks at phase start = 1002step 119322197: M = bell blocks at phase start = 1083step 144732311: M = bell blocks at phase start = 1168step 174085265: M = bell blocks at phase start = 1252step 207484435: M = bell blocks at phase start = 1326step 244435833: M = bell blocks at phase start = 1401step 285517799: M = bell blocks at phase start = 1469step 331301633: M = bell blocks at phase start = 1556step 382417731: M = bell blocks at phase start = 1642step 438884121: M = bell blocks at phase start = 1705step 501203395: M = bell blocks at phase start = 1791step 568808345: M = bell blocks at phase start = 1887step 643095903: M = bell blocks at phase start = 1957step 723172281: M = bell blocks at phase start = 2025step 809229495: M = bell blocks at phase start = 2106step 902342053: M = bell blocks at phase start = 2188step 991609360: M = bell blocks at phase start = 2263
|W| = counter cellslast 47
757419.9e8log xstep 41: |W| = counter cells = 8step 64: |W| = counter cells = 7step 163: |W| = counter cells = 7step 362: |W| = counter cells = 13step 669: |W| = counter cells = 19step 1104: |W| = counter cells = 25step 1675: |W| = counter cells = 19step 2574: |W| = counter cells = 25step 10067: |W| = counter cells = 50step 128733: |W| = counter cells = 19step 529171: |W| = counter cells = 29step 1428457: |W| = counter cells = 31step 2974083: |W| = counter cells = 17step 5636701: |W| = counter cells = 33step 9167327: |W| = counter cells = 41step 13840601: |W| = counter cells = 17step 19709255: |W| = counter cells = 67step 27284505: |W| = counter cells = 16step 36981311: |W| = counter cells = 61step 48739545: |W| = counter cells = 50step 62765319: |W| = counter cells = 23step 79028529: |W| = counter cells = 49step 97840939: |W| = counter cells = 40step 119322197: |W| = counter cells = 31step 144732311: |W| = counter cells = 45step 174085265: |W| = counter cells = 52step 207484435: |W| = counter cells = 49step 244435833: |W| = counter cells = 31step 285517799: |W| = counter cells = 51step 331301633: |W| = counter cells = 37step 382417731: |W| = counter cells = 41step 438884121: |W| = counter cells = 71step 501203395: |W| = counter cells = 55step 568808345: |W| = counter cells = 31step 643095903: |W| = counter cells = 51step 723172281: |W| = counter cells = 75step 809229495: |W| = counter cells = 69step 902342053: |W| = counter cells = 57step 991609360: |W| = counter cells = 47
W as wall gaps (o = 00 hole, # = 11 bump)last 1o 1o 5o 1o 1o 3o 1o 15o 3o 1o 1o 5o 3o 1o 2# 2o
not plottable
Template comparisonBMO7.v: partly applies · the nearest solved proof, what carries over, and the transitions that differ
01
A1RB1RF
B1RC0RA
C1LD1REtpl 1RC
D1LE0LE
E0RA0LD
F0RB---

differs from the template

file
BMO7.v
module
—
machine
1RB1RF_1RC0RA_1LD1RC_1LE0LE_0RA0LD_0RB--- (1 transition apart)
diff
C1: 1RC (BMO 7) -> 1RE (ours); all other 11 transitions equal
note
Left bell bounce (BMO7 LIncs) holds here 36/36; binary RInc fails on every odd counter (16/40), BigStep shape 3/8 with non-binary right side. Same layout, new counter.
Proof strategy & riskshow the formal proof will go · 3 risks to watch

Keep BMO7's layout: Longitudinal sideRLs for bell bounces (reuse LIncs), a new ternary Inc lemma over frames (ind on digits, DivModCases mod 3). Next stage: close the Eat step by enumerating reachable counter shapes; if finite-parametric, prove it with a WF invariant + progress_nonhalt_cond (BMO7 pattern), else a verified checker over frame lists.

  • ▲Eat step not closed: phase-start counters irregular (dN 1 in ~half of phases, else 4..38).
  • ▲If eat outcomes depend on counter digits pseudo-randomly, this becomes a cryptid-like case.
  • ▲Larger than BMO7 (441 lines): two-level counter + eat lemma family; likely >15 KB.
Stats & provenance109 steps simulated · 4,585 cells · the status in full · files
simulated
109 steps
tape
4,585 cells · 2,285 nonzeros
growth
bell M ~ t^0.342; 312 phases by 1e9; span -312..4272
status now
Funded stage prove_margin (2026-10-10) ended by its exit rule: failed bound -> parked, cryptid-margin suspect. Fast exact phase map (1321/1321 logged starts, 40/40 direct one-phase checks) extends the orbit to phase 11798, M=114,554 (~9.7e13 steps): no halt, margin k_align <= M-1 at every start, max ratio 0.467, no drift toward 1. But the margin is not provable from counter structure: random reachable-looking counters (aligned, digits 1, random or orbit widths) break it in 7/200 and 4/200 runs (up to 2.84x), and it depends on the exact bell: orbit phase 10666 with bell 102,051 instead of 102,052 gives next ratio 0.979 (orbit: 0). No tested break led to halting (0/400), so not flagged CRYPTID_CANDIDATE. Rules (J-rule, Gap-Inc, J-crossing, walk), G1 and the fast map remain valid for any later attempt. (status.json, 2026-10-10)
observer's note
Bell/marker and base-3 counter rules validated; eat step is N-independent but its closed form is open. No Collatz-style rule found (values grow polynomially), so not flagged cryptid yet.
files
observe.json · notes.md · status.json

Proof & checks

No proof work yet.

Files

machines/<tm>/: 8 entries · raw notes, status, scripts, images

namesizechanged
notes.md ↓24 KB2026-10-10 13:25
status.json ↓1.0 KB2026-10-10 13:25
observe.json ↓13 KB2026-10-10 04:41
deepen.json ↓16 KB2026-10-10 13:25
decisions/1 item2026-10-10 13:25
img/9 items2026-10-10 00:51
scripts/48 items2026-10-10 13:23
work/29 items2026-10-10 00:51
status.json in full
{
 "tm": "1RB1RF_1RC0RA_1LD1RE_1LE0LE_0RA0LD_0RB---",
 "status": "STUCK",
 "stage": "funded:prove_margin",
 "updated": "2026-10-10",
 "reason": "Funded stage prove_margin (2026-10-10) ended by its exit rule: failed bound -> parked, cryptid-margin suspect. Fast exact phase map (1321/1321 logged starts, 40/40 direct one-phase checks) extends the orbit to phase 11798, M=114,554 (~9.7e13 steps): no halt, margin k_align <= M-1 at every start, max ratio 0.467, no drift toward 1. But the margin is not provable from counter structure: random reachable-looking counters (aligned, digits 1, random or orbit widths) break it in 7/200 and 4/200 runs (up to 2.84x), and it depends on the exact bell: orbit phase 10666 with bell 102,051 instead of 102,052 gives next ratio 0.979 (orbit: 0). No tested break led to halting (0/400), so not flagged CRYPTID_CANDIDATE. Rules (J-rule, Gap-Inc, J-crossing, walk), G1 and the fast map remain valid for any later attempt.",
 "funded": {
  "option": "prove_margin",
  "date": "2026-10-10"
 }
}