{
  "step": "C420",
  "status": "passed",
  "assertions_passed": 35,
  "checks": [
    "fixed source gap ('Noah birth', 'E')",
    "E2 exact composition Noah birth",
    "fixed source gap ('Noah birth', 'E2')",
    "fixed source gap ('Noah birth', 'P')",
    "nonintegral fixed2K output ('Noah birth', 'P')",
    "fixed source gap ('Noah birth', 'J')",
    "nonintegral fixed2K output ('Noah birth', 'J')",
    "fixed source gap ('Shem birth', 'E')",
    "E2 exact composition Shem birth",
    "fixed source gap ('Shem birth', 'E2')",
    "fixed source gap ('Shem birth', 'P')",
    "nonintegral fixed2K output ('Shem birth', 'P')",
    "fixed source gap ('Shem birth', 'J')",
    "nonintegral fixed2K output ('Shem birth', 'J')",
    "fixed source gap ('Noah death', 'E')",
    "E2 exact composition Noah death",
    "fixed source gap ('Noah death', 'E2')",
    "fixed source gap ('Noah death', 'P')",
    "nonintegral fixed2K output ('Noah death', 'P')",
    "fixed source gap ('Noah death', 'J')",
    "nonintegral fixed2K output ('Noah death', 'J')",
    "fixed source gap ('Shem death', 'E')",
    "E2 exact composition Shem death",
    "fixed source gap ('Shem death', 'E2')",
    "fixed source gap ('Shem death', 'P')",
    "nonintegral fixed2K output ('Shem death', 'P')",
    "fixed source gap ('Shem death', 'J')",
    "nonintegral fixed2K output ('Shem death', 'J')",
    "fixed source gap ('selected Flood boundary', 'E')",
    "E2 exact composition selected Flood boundary",
    "fixed source gap ('selected Flood boundary', 'E2')",
    "fixed source gap ('selected Flood boundary', 'P')",
    "nonintegral fixed2K output ('selected Flood boundary', 'P')",
    "fixed source gap ('selected Flood boundary', 'J')",
    "nonintegral fixed2K output ('selected Flood boundary', 'J')"
  ],
  "source_checks_passed": 14,
  "source_checks": [
    "frozen PREVIOUS_CERTIFICATE.json",
    "frozen PREVIOUS_RESULTS.json",
    "frozen PREVIOUS_DATA.json",
    "frozen PREVIOUS_CHECKPOINT.md",
    "frozen PREVIOUS_NEXT_STEP.json",
    "frozen File_18.md",
    "frozen File_09.md",
    "frozen C286_DATA.json",
    "frozen C287_DATA.json",
    "frozen C271_REGISTER.json",
    "predecessor PREVIOUS_RESULTS.json",
    "predecessor PREVIOUS_DATA.json",
    "predecessor PREVIOUS_CHECKPOINT.md",
    "predecessor PREVIOUS_NEXT_STEP.json"
  ],
  "canonical_or_graph_edits": false,
  "check_scope": "Finite source-labelled calculation; counts are verification inventory, not witness counts."
}