{
  "step": "C428",
  "status": "completed",
  "title": "Complete fixed 17K joins of the regular 2K census",
  "previous_certificate_sha256": "11a2ec3f40138f2c6359645beb4589018758042ae477e5bb3fe0ec34f592c5dc",
  "bindings": {
    "step": "STEP.json",
    "source_manifest": "SOURCE_MANIFEST.json",
    "report": "490d_C428_Complete_Fixed_17K_Joins_of_the_2K_Census_20260924.md",
    "checkpoint": "490d_Mirror_Checkpoint_After_C428_20260924.md",
    "data": "evidence/DATA.json",
    "results": "evidence/RESULTS.json",
    "calculation": "evidence/CALCULATION.py",
    "verifier": "evidence/check.py",
    "next_step_decision": "NEXT_STEP_DECISION.json",
    "replay": "REPLAY.json",
    "control_integrity": "CONTROL_INTEGRITY.json",
    "readme": "README.md"
  },
  "step_sha256": "e80d0642e74a6524e3350f9691d56742bb5d9bf7e45e5fa78c5585bf1ae76877",
  "source_manifest_sha256": "b253f7ec3e5956bf2b251bad0742367021b701ffc00bdb6f512179a77036ada3",
  "report_sha256": "e954ea1d1d36d8564841f49d07a7df6dde79fce223a217047080030ec44034e8",
  "checkpoint_sha256": "c302b3a0cf556eed4e59a607ee60c0bf75119bc111546d0955248ceb0c618d66",
  "data_sha256": "b6e4a14355c4021e9cce50ce46cdd66e28706906bf65fab3fa4e0ae3e3d42430",
  "results_sha256": "a1ca16651fa3b89b924e9cde9cf5def5ae022a1eb7aa21f390aa04370aa16b02",
  "calculation_sha256": "5571c9b0ca3d89499583712a577730d7f5138a1d65949ce93581a38e4bef17c1",
  "verifier_sha256": "54ec196818f7b9bb5e18af36e2632264bb5c010834b6718e8acd860ef2eaae96",
  "next_step_decision_sha256": "43c0f87e852dc859d10613b7d0f26c709e8d1353daab816b6b92482d069769bd",
  "replay_sha256": "3569900b2648ea1a8f85db1b4ad9817b23e5798a6268064a9110e0e178a6b704",
  "control_integrity_sha256": "231cf3e4dc0edc6ff70781aa9b16678248460145408355e421bef7a9d565b260",
  "readme_sha256": "b93344072cf0c4bf4d7aeabf045e246ba155160e044679fe1e4162c779e0bbed",
  "assertions_passed": 160,
  "source_checks_passed": 16,
  "main_result": "All26 regular2K pairs × six cumulative2K Shem/Flood pairs give156 fixed17K trials. Four coordinate joins survive, with six labelled regular realizations: precisely C287 i2–i5, all T1. Companion i2/i4 remain valid source rectangles; later primary i3/i5 operator qualifications remain separate. T2/T3/T4 add no Mirror branch.",
  "limits": "Completeness is restricted to the frozen cumulative and regular registers and the fixed17K equations. Existing companion rectangles are not newly admitted operator paths.",
  "canonical_or_graph_edits": false,
  "new_independent_agent_review": false,
  "next_step_executed": false,
  "next_proposed_step": "Complete the fixed-upper gap-scaling inventory for all26 source2K pairs under E, E², P and J. Record every sourced output and distinguish squared-E endpoints from two sourced E steps, retaining the four context-template labels."
}