BB(6) hunt
Machines / 740 line 715

1RB0RC_1LC0RB_1LD0LD_1RA1LE_---0LF_1LB1LF

740 line 715SkippedBouncer + Chaotic Edgebbchallenge ↗Explorer

Where it stands

Skipped

User accepted the recommendation to defer this family behind stronger initial leads on 2026-10-14.

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

A 20-cell periodic region coexists with a much larger irregular region whose compressed description grows.

Status
Skippeddeferred · updated 2026-10-14T10:06:30.232473-07:00Parked · User accepted the recommendation to defer this family behind stronger initial leads on 2026-10-14.
idle since Oct 14 10:06 · status.json 2026-10-14T10:06:30.232473-07:00
Class
Bouncer + Chaotic Edgeours: sheet Bouncer + Chaotic Edge ≠ ours Bouncer with period-20 bulk and unresolved irregular boundary · low confidence
On the list
line 639 of BB6_holdouts_663.txt · historical 740 line 715
eqv ×1sim 1e13UBRRBA
Your calls on file 2
next
Retain evidence; no further research scheduled for this family.
decision.json · answered 2026-10-14: defer
Defer line 715 behind line 593, or fund a 30-minute irregular-region study? Decisions →

Mechanism

How it works: 3 notes
  • The 100-million-step snapshot has 274 consecutive copies of a 20-cell word. The long-run image shows a regular left region and irregular material extending toward the right.
  • With periods through 64, the 1m, 10m and 100m snapshots require 104, 267 and 866 tokens. This measured growth makes a small fixed collection of bulk-length counters less plausible than for the other candidate; it does not prove chaos.
  • The block-20 qsim reached 8,156,594 exact steps with no rules in 100,000 macro loops. Its endpoint agrees with a direct C rerun. Direct C simulation separately reached 100 million steps without a halt.

Figures

Fig 1 · Early bounces, first 200,000 steps

Follow the moving head and compare the two outer edges.

Early bounces, first 200,000 steps
bbchallenge-defaultStart blankRows every 100 stepsWindow cells -585..301, 1 px = 1 cellsColors 1 0 or unvisited head after a right move head after a left move
Rows: 0..200,000, 2001 rows; time runs downward · Window: sampled columns when scale exceeds 1
Fig 2 · Growth through 10 million steps

Compare regular bands with the irregular boundary region; rows and columns are sampled.

Growth through 10 million steps
bbchallenge-defaultStart blankRows every 10,000 stepsWindow cells -4485..2761, 1 px = 4 cellsColors 1 0 or unvisited head after a right move head after a left move
Rows: 0..10,000,000, 1001 rows; time runs downward · Window: sampled columns when scale exceeds 1
More figures (1)Fig 3: First 10,000 steps, site view
Fig 3 · First 10,000 steps, site view

Compare the initial widening trace before the much larger sampled views.

First 10,000 steps, site view
bbchallenge-defaultStart blankRows steps 0..9999 squeezed to 500 display rowsWindow cells -200..199, 1 px = 1 cellColors 1 0 or unvisited head after a right/left move
Rows: each row blends source rows 20y+9 and 20y+10 · Colors: pale colors are blended
Rulesnone yet: the exact tape rewrites the proof will formalize
—
Compressed historythe tape as Observed span and snapshot compression; no invariant skeleton established at 3 moments: where the rules are read off
Observed span and snapshot compression; no invariant skeleton established
steplohiK64_tokens
1,000,000-1,365793104
10,000,000-4,4852,761267
100,000,000-14,4458,919866
lolast -14,445
-1,365-14,4451e61e8step 1000000: lo = 1365step 10000000: lo = 4485step 100000000: lo = 14445
hilast 8,919
8,9197931e61e8step 1000000: hi = 793step 10000000: hi = 2761step 100000000: hi = 8919
K64_tokenslast 866
8661041e61e8step 1000000: K64_tokens = 104step 10000000: K64_tokens = 267step 100000000: K64_tokens = 866
Template comparisontemplate: unknown · the nearest solved proof, what carries over, and the transitions that differ
01
A1RB0RC
B1LC0RB
C1LD0LD
D1RA1LE
E---0LF
F1LB1LF
file
—
module
—
machine
—
diff
—
note
Preflight found no existing machine-table conjugacy or current open-PR overlap. No proof template selected.
Proof strategy & riskshow the formal proof will go · 3 risks to watch

Rank second; stop before invariant work. A future study would need a symbolic description of the growing irregular region, not only the visible period-20 bulk.

  • ▲The unexplained edge may need a substantially larger symbolic state.
  • ▲No global exclusion of the E0 halting precursor is proved.
  • ▲Finite runs and accelerator rules are observational evidence only.
Stats & provenance108 steps simulated · 23,365 cells · the status in full · files
simulated
108 steps
tape
23,365 cells · 18,374 nonzeros
growth
Expanding span in the measured prefix; no asymptotic law established.
status now
User accepted the recommendation to defer this family behind stronger initial leads on 2026-10-14. (status.json, 2026-10-14T10:06:30.232473-07:00)
observer's note
Initial observation complete; full mechanism confidence is low. Halting status remains open; no proof or invariant claimed.
files
observe.json · notes.md · status.json

Proof & checks

No proof work yet.

Files

machines/<tm>/: 6 entries · raw notes, status, scripts, images

namesizechanged
notes.md ↓4.2 KB2026-10-14 10:06
status.json ↓821 B2026-10-14 10:06
observe.json ↓5.9 KB2026-10-13 18:25
decision.json ↓1.5 KB2026-10-14 10:06
img/3 items2026-10-13 18:25
observation/26 items2026-10-13 18:26
status.json in full
{
 "tm": "1RB0RC_1LC0RB_1LD0LD_1RA1LE_---0LF_1LB1LF",
 "status": "SKIPPED",
 "stage": "deferred",
 "updated": "2026-10-14T10:06:30.232473-07:00",
 "updated_utc": "2026-10-14T17:06:30.232473+00:00",
 "owner": "astra",
 "holdout_line": 715,
 "reason": "User accepted the recommendation to defer this family behind stronger initial leads on 2026-10-14.",
 "confidence": "low",
 "observation_complete": true,
 "proof_started": false,
 "formal_checker_run": false,
 "recommendation": "Rank second; stop before invariant work. A future study would need a symbolic description of the growing irregular region, not only the visible period-20 bulk.",
 "next_action": "Deferred by user decision.",
 "observation_completed": "2026-10-13",
 "next": "Retain evidence; no further research scheduled for this family."
}
observe.json contract (tools/README-card.md):
1 contract warning
  • rank: missing