# C271 evidence packet

Completed 24 September 2026. Continues the existing 490d Unified Chronology research after C270.

Read `490d_C271_SP_Three_Gear_Radius_Register_20260924.md`, then `490d_Mirror_Checkpoint_After_C271_20260924.md`. C272 is proposed, not executed.

## Reproduce the calculation

From this directory, using Python 3 and its standard library:

```sh
python evidence/check_c271.py --output /tmp/490d_c271_replay
```

The verifier uses ten frozen inputs in `sources/`, listed with sizes and SHA-256 values in `SOURCE_MANIFEST.json`. It passes 271 exact assertions and writes six files:

- `REGISTER_IMAGES.json`: twelve typed source records, cumulative ancestry and all 24 seasonal components.
- `PAIR_MATRIX.json`: all 36 Noah/Flood pairings, six exact matches and thirty nonzero residuals.
- `CUMULATIVE_COVERAGE.json`: covered indices 2–7, omitted indices 0–1, generated regular images and opposite-role local co-locations.
- `MATCHED_FAMILIES.json`: six source-bound radius families and their seasonal ratios.
- `RESULTS.json`: assertion ledger and bounded outcomes.
- `COMPONENTS.csv`: compact original, reflected, cumulative and local phase ledger.

`REPLAY.json` records byte-identical reproduction of these six files. The authored report and checkpoint are not replay outputs. Independent mathematical, source-binding and final reviews are in `evidence/`.

## Integrity and interpretation

`SCOPE.json` fixes the finite twelve-event register and all maps before verifier execution. `CONTROL_INTEGRITY.json` confirms unchanged originals, the 208-node/382-duration-edge C127 graph and the C265 certificate. Absolute original paths are provenance references; reproduction uses the included frozen copies and does not require those paths.

`CERTIFICATE.json` links to C270 and binds the report, checkpoint, source manifest, results, replay and control-integrity record. `ARTIFACT_MANIFEST.json` inventories all other payloads, including the certificate, while excluding itself. The certificate does not hash itself or the artifact manifest.

Primary/start supplies radii 2,4,6 and companion/close supplies 1,3,5. Only the outer row retains the seasonal ratio 25/23. The source coverage is six boundary records spanning five elapsed years in each cumulative field, not the full eight-record/seven-year field. Source identities, Flood event boundaries and person companions remain distinct. No new independent witness, graph edge, universal chronology action, altered comparison map or wider Gear permission is asserted.

Regular Gears remain Noah/Shem/Flood only. Canonical sources and the graph are unchanged. C272 has not been executed.