# C273 synthesis evidence packet

Completed 24 September 2026. Continues the existing 490d Unified Chronology research after C272.

Read `490d_C273_529_Dependency_Synthesis_C266_C272_20260924.md`, then `490d_Mirror_Checkpoint_After_C273_20260924.md`. C274 is proposed, not executed.

## Reproduce the targeted checks

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

```sh
python evidence/check_c273.py --output /tmp/490d_c273_replay
```

The verifier uses 43 frozen immediate inputs in `sources/`, listed in `SOURCE_MANIFEST.json`, plus the authored `CLAIMS_SPEC.json`. It checks the C265→C272 report/result certificate chain and selected equations without rerunning the old campaigns. It passes 156 checks and writes six files:

- `CLAIM_LEDGER.json`: seven input groups, ten derived groups and one assessment group, with dependencies and source references.
- `DEPENDENCY_DAG.json`: ordered nodes and dependency edges; these are not new chronological graph edges.
- `CORE_EQUATIONS.json`: conditional placement recovery, local fields, source rectangle, induced maps and chart relations.
- `LIMITS_REGISTER.json`: unresolved premise selection, operator differences, finite source limits and geometric roles.
- `RESULTS.json`: targeted check ledger and retained historical certificate metadata; historical counts are not rerun totals.
- `CLAIM_LEDGER.csv`: compact claim table.

`REPLAY.json` records byte-identical reproduction. The authored report and checkpoint are not replay outputs. `evidence/REVIEW_NOTES.md` records an author consistency review. No new independent-agent review is claimed. Machine checks establish integrity, reference/order validity and the stated arithmetic; they do not prove the editorial dependency semantics, formal minimality or the scholarly assessment.

## Integrity and scope

`SCOPE.json` confines this step to C266–C272 and their immediate dependencies. `CONTROL_INTEGRITY.json` confirms unchanged original inputs, the 208-node/382-duration-edge C127 graph and the C265 certificate. Absolute original paths are provenance references; reproduction uses included frozen copies.

`CERTIFICATE.json` chains to C272 and binds the synthesis, checkpoint, source manifest, authored claim specification, results, replay and control-integrity record. `ARTIFACT_MANIFEST.json` inventories all other payloads, including the certificate, and excludes itself. The certificate does not hash itself or the artifact manifest.

The core result is a qualified dependency account. The central translations are fixed once their joining conditions are imposed; the large charts are fixed once their calibration is imposed. Whether a common source chronology rule requires those premises remains unestablished. C274's proposed omission audit has not been executed.

Capture now, canonize later. Regular Gears remain Noah/Shem/Flood only. No canonical edit, new source event, graph amendment, broader numerical search, new axis, z-law or primer reopening is included.