{
 "tm": "1RB0RF_1RC0LD_1RD0RA_1LE0LC_1LB0LE_0RC---",
 "rank": null,
 "class_sheet": "Bell eats counter",
 "class_guess": "Binary counter at the left wall eats a 6-cell reservoir; each overflow fossilizes the counter's binary residue as junk that the next cycle re-reads",
 "confidence": "low",
 "summary": "Left-wall binary counter eats a 010001 reservoir; overflow leaves a binary-residue junk word; spurts are residue-timed",
 "mechanism": [
  "Counter pass (rules P0/P1, 80/80): 0^inf <D (011)^a (010001)^b x (010001)^c, x = one-cell phase defect. One pass moves the defect 2^a words right and adds a digit: (a,b,c) -> (a+1, b+2^a, c-2^a) while c >= 2^a.",
  "Overflow (rule O, 24/24): when c < 2^a the whole sea is re-laid as a 3-cell field, 0^inf J (011)^(2b+2c) C>, where J is a junk word of exactly 3a+4 cells (the counter's partial state, i.e. a binary residue). Halting needs A to read 1 with a 1 on its right (A1 -> 0RF, F1 undefined). No halt to 2e10 (span 75,979, 36,061 ones).",
  "Cycle: J (101)^n B> -> J' (101)^n' B> (n' - n = +28..+72 at the 34k level) or a spurt that doubles the field, 1 0^3 (011)^(2n+12..24) C>. J is the previous counter's residue (c0 + 2^a0) mod 2^A, and it decides which: plateaus of 1, 1, 9, 3 and 31 cycles, spurts at 1.1e7, 3.0e7, 3.3e8, 9.9e8, 1.88e10."
 ],
 "diagrams": [
  {
   "mode": "default",
   "png": "img/default_site_1e4.png",
   "html": null,
   "steps": 10000,
   "caption": "bbchallenge default view, first 10,000 steps",
   "title": "bbchallenge default view, first 10,000 steps",
   "why": "The site's view. The tape grows left in steps; the fine stripes are the 3- and 6-cell fields being rewritten.",
   "primary": true,
   "start": "blank",
   "rows": "10,000 steps squeezed into 500 px rows (1 px row = 20 steps; the site blends neighbouring steps)",
   "window": "cells -200..199, 1 px = 1 cell",
   "legend": "white = 1, black = 0 or never visited, red/green = head after a right/left move",
   "style": "bbchallenge-default"
  },
  {
   "mode": "custom",
   "png": "img/span_logt.png",
   "html": null,
   "steps": 20000000000,
   "caption": "Span against log step to 2e10: plateaus and spurts",
   "title": "Span vs log(step): plateaus and spurts",
   "why": "Each flat stretch is many cycles; each steep rise is one spurt cycle. Compare the plateau lengths.",
   "primary": true,
   "start": "blank",
   "rows": "chart, not a tape: x = log10(step) from 6 to 10.3 (vertical gridline at each power of 10), y = span hi-lo+1 at each new record",
   "window": "cells 0..80000, 1 px = 223 cells (vertical axis = span; chart gridline every 10,000 cells; horizontal axis = log10 step 6..10.3)",
   "legend": "blue = span (cells visited), grey = gridlines, white = background",
   "style": "custom"
  },
  {
   "mode": "every:40000",
   "png": "img/fieldmap_cycle.png",
   "html": null,
   "steps": 30000000,
   "caption": "One ordinary cycle as a field map, 1 px = 6 cells",
   "title": "One ordinary cycle: the reservoir is eaten",
   "why": "Rows go down in time. Watch the orange/blue boundary (the phase defect) move right until blue is gone.",
   "primary": true,
   "start": "mid-run: step 110,000,000",
   "rows": "every 40000 steps (751 rows, 3e7 steps: one cycle plus the start of the next)",
   "window": "cells -7850..297, 1 px = 6 cells (one 6-cell block per pixel; block colour by content)",
   "legend": "grey = 3-cell field (011 in any phase); orange = 010001 left of the phase defect; blue = 010001 right of it (the reservoir); green/purple/cyan/olive = 010001 in other phases; red = any other block (junk, defect); black = blank; white = head",
   "style": "custom"
  },
  {
   "mode": "every:100000",
   "png": "img/fieldmap_spurt.png",
   "html": null,
   "steps": 66000000,
   "caption": "The spurt cycle at 2.6e8-3.3e8, field map",
   "title": "The spurt cycle: the field doubles leftward",
   "why": "Same colours as the cycle map. Here the left edge advances on every sweep instead of the defect.",
   "primary": false,
   "start": "mid-run: step 261,900,000",
   "rows": "every 100000 steps (661 rows, 6.6e7 steps, through the spurt that ends at step 326,852,586)",
   "window": "cells -16,778..363, 1 px = 6 cells (one 6-cell block per pixel; block colour by content)",
   "legend": "grey = 3-cell field (011 in any phase); orange/blue/green/purple/cyan/olive = 010001 in its six phases; red = any other block; black = blank; white = head",
   "style": "custom"
  }
 ],
 "history": {
  "skeleton": "0^inf <D 011^a 010001^b 0 010001^c 0^inf",
  "vars": [
   "a",
   "b",
   "c"
  ],
  "rows": [
   {
    "step": 56559588,
    "values": [
     3,
     13,
     1277
    ]
   },
   {
    "step": 56564129,
    "values": [
     4,
     21,
     1269
    ]
   },
   {
    "step": 56579358,
    "values": [
     5,
     37,
     1253
    ]
   },
   {
    "step": 56634395,
    "values": [
     6,
     69,
     1221
    ]
   },
   {
    "step": 56842776,
    "values": [
     7,
     133,
     1157
    ]
   },
   {
    "step": 57652757,
    "values": [
     8,
     261,
     1029
    ]
   },
   {
    "step": 60845586,
    "values": [
     9,
     517,
     773
    ]
   },
   {
    "step": 73522703,
    "values": [
     10,
     1029,
     261
    ]
   }
  ]
 },
 "rules": [
  {
   "name": "P1 counter pass, 1-defect",
   "from": "0^inf <D 011^a 010001^b 1 010001^c 0^inf",
   "to": "0^inf <D 011^(a+1) 010001^(b+2^a) 1 010001^(c-2^a) 0^inf",
   "steps": null,
   "cases": "c >= 2^a; a = 0..9, b = 1..2^a+60, c = 2^a..2^a+300",
   "validated": {
    "instances": 40,
    "passed": 40
   },
   "source": "manual"
  },
  {
   "name": "P0 counter pass, 0-defect",
   "from": "0^inf <D 011^a 010001^b 0 010001^c 0^inf",
   "to": "0^inf <D 011^(a+1) 010001^(b+2^a) 0 010001^(c-2^a) 0^inf",
   "steps": null,
   "cases": "c >= 2^a; a = 0..9, b = 1..2^a+60, c = 2^a..2^a+300",
   "validated": {
    "instances": 40,
    "passed": 40
   },
   "source": "manual"
  },
  {
   "name": "O overflow (shape only)",
   "from": "0^inf <D 011^a 010001^b x 010001^c 0^inf, x in {0,1}",
   "to": "0^inf J 011^(2b+2c) C> 0^inf (at the next right record), |J| = 3a+4 cells, J not yet characterised",
   "steps": null,
   "cases": "c < 2^a; a = 0..7",
   "validated": {
    "instances": 24,
    "passed": 24
   },
   "source": "manual"
  },
  {
   "name": "Cycle map (observed only)",
   "from": "0^inf J 101^n B> 0^inf",
   "to": "0^inf J' 101^n' B> 0^inf, n' - n in +9..+75; or spurt 0^inf 1 0^3 011^(2n+k) C> 1 0^inf, k in 12..24",
   "steps": null,
   "cases": "which branch: decided by J (a binary residue); not characterised",
   "validated": {
    "instances": 0,
    "passed": 0
   },
   "source": "manual"
  }
 ],
 "template": {
  "file": "machines/1RB0RF_1RC0RB_1LD0RA_1LE0LD_1RB0LC_1LA---/1RB0RF_1RC0RB_1LD0RA_1LE0LD_1RB0LC_1LA---.v",
  "module": null,
  "machine": "1RB0RF_1RC0RB_1LD0RA_1LE0LD_1RB0LC_1LA---",
  "diff": "d = 4 (start A); SOMDC_Class1.v nonhalt (1LB---_1RC0RF_1LD1RB_1LE0LD_1RB0LB_1RB0RA, start F) also d = 4",
  "applies": "no",
  "note": "W4-3 (ours, killed) is a multi-level counter on 00/11 defects whose fossils are inert (block lengths only matter mod 4). Here the counter's leftover is fossilized as junk J and is re-read: J decides the next cycle's start and whether it spurts. W4-3's RIncs-style scan does not cover a junk word that carries a binary residue. SOMDC_Class1 shares the d = 4 distance only; its rule set (one structural counter) has no overflow-to-junk step."
 },
 "strategy": "A proof needs a closed description of the junk words J and the cycle map (J, n) -> (J', n') or spurt, for every reachable J. That is an arithmetic map on n and a binary residue (c0 + 2^a0) mod 2^A, with the spurt as one residue class. Parked unless that map turns out to be a clean binary rule.",
 "risks": [
  "Residue-driven: the cycle outcome depends on a ~12-bit residue of a slowly growing n; plateau lengths 1, 1, 9, 3, 31 look irregular (possible Collatz-like map).",
  "The junk J and the junk-processing phase (several sweeps with right records before each counter starts) are not characterised.",
  "Waves 4 and 5 rejected it; the only fixed-constant rule rulefit found (E1(2n,632-n)) is one finite pass of rule P."
 ],
 "checkpoint_questions": [
  {
   "text": "Fig 3: does the orange/blue boundary (the phase defect) move right in passes until the blue reservoir is gone, as rules P0/P1 say?",
   "figs": [
    2
   ],
   "kind": "check"
  },
  {
   "text": "Fig 2: plateaus of 1, 1, 9, 3 and 31 cycles between spurts. Park B-4 as residue-driven (STUCK), or fund one 2 h stage to characterise J and the cycle map?",
   "figs": [
    1
   ],
   "kind": "decision"
  }
 ],
 "discord_check": null,
 "stats": {
  "simulated_steps": 20000000000,
  "cells": 75979,
  "nonzeros": 36061,
  "growth": "span doubles in spurts: 1.7k -> 3.5k (1.1e7) -> 7.4k (3.0e7) -> 16.7k (3.3e8) -> 34.2k (9.9e8) -> 75.0k (1.88e10); in between, plateaus grow ~30-190 cells per cycle; no halt to 2e10"
 },
 "status": "STUCK",
 "status_reason": "Parked at observe (cap 1 h): counter passes and overflow shape validated (104/104), but the cycle map runs on a binary residue fossilized as junk; spurts are residue-timed (plateaus of 1, 1, 9, 3, 31 cycles)."
}