Initial observation: holdout line 715

Machine: 1RB0RC_1LC0RB_1LD0LD_1RA1LE_---0LF_1LB1LF. Owner: Astra. Halting status: open.

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

Recommendation and stopping point

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.

Confidence is high in the finite measurements, medium in the visible bouncer/periodic-bulk description, and low in a complete mechanism. No arithmetic return recurrence has been established, so no claim of pseudo-random arithmetic is made. Stop before constructing an unsupported invariant. This is an observation result, not a kill claim.

Measurements

The longest primitive-period run in the 100m snapshot has period 20, with 274 full copies and 5,480 cells. observation/periodic-runs.json records its exact word and offset from the visited left edge. Rotations of the word can arise from the chosen starting cell. The period search and byte equality certify the sampled substring only.

The qsim endpoint is 8,156,594 steps after 100,000 macro loops, with 0 rules and 0 Collatz rules. Reported rule statistics: {"count": 0, "types": {}, "uses": {}}. These are external simulator facts, not Rocq certificates. The default block finder chose block size 1 and gave no rules for either candidate.

A separate direct C run to 8,156,594 agrees with the block-20 qsim on state, direction, step number, and all nonblank cells relative to the head. This comparison does not independently compare qsim's absolute head position, which its exported snapshot does not provide. The farthest direct run reaches 100,000,000 steps without a halt, visits [-14,445, 8,919], and has 18,374 ones.

Mechanism boundary

E is entered only by D1=1LE. Thus D reading 1 with a 0 immediately to its left reaches E0, the undefined transition. Excluding this state-sensitive pattern globally remains unproved.

No finite macro rule was promoted into an invariant, and no Coq work was attempted. The diagrams of periodic regions and the compression sizes do not show that those regions will retain their structure forever.

Artifacts and reproducibility

• index.html: labeled observation card, rendered from observe.json.
• img/first-200k.png: rows every 100 transitions through 200,000; full cell resolution.
• img/first-10m.png: rows every 10,000 transitions through 10,000,000; column scale is stated on the card. These are sampled rows, not a continuous trace.
• img/default-10k.png: the standard site view of the first 10,000 steps.
• observation/direct-100m.jsonl: direct snapshots every million transitions plus the final configuration.
• observation/qsim-block20.jsonl: accelerated probe with exact counts; default probe is qsim-30s.jsonl.
• observation/direct-qsim-crosscheck.jsonl and qsim-direct-agreement.json: independent direct endpoint and comparison.
• observation/compressed-k64.json, compressed-samples.json, periodic-runs.json: lossless compressed samples and exact periodic-substring measurements.
• Every simulator/diagram invocation has a neighboring .meta.json recording its command, elapsed time, memory preflight, load, and 6,000,000-kB virtual-memory limit.

The initial runner is astra/observe_bouncers_593_715.py; the analysis/card-data builder is astra/summarize_bouncers_593_715.py. Commands for additional bounded probes are preserved in the per-command metadata. Runs used one worker, nice level 10, MemAvailable above 10 GB, and one-minute load below 28. No existing proof, vendor, shared tools, mailbox or git-state edits were needed. The card linter's sole remaining warning is the intentionally unset historical pool rank; the exact current holdout line is stored separately.

AI assistance: GPT-6 Astra (OpenAI).

Priority decision — 2026-10-14

The user said: “Follow your recommendations for the 5.” Recorded defer; this family is deferred.