{
  "step": "C387",
  "status": "completed",
  "date": "2026-09-24",
  "title": "Companion and502/98 controls for the E/J square",
  "previous_certificate_sha256": "734a24535c34afed4ac46aa4d12c1eceb24664b0f6f84a12a5c7cb581733b45c",
  "bindings": {
    "step": "STEP.json",
    "source_manifest": "SOURCE_MANIFEST.json",
    "report": "490d_C387_E_J_Companion_and_Shem_Mode_Controls_20260924.md",
    "checkpoint": "490d_Mirror_Checkpoint_After_C387_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": "627f199cd88a7aac5fed5a1d22955f8dab06c0bbe4d1db19dbfeacfcf862a690",
  "source_manifest_sha256": "27b2c28283347b98ffc2bdc737f3506130998f7ef1f117af0cbe31e6354e6680",
  "report_sha256": "0a2b3e08947191613a0117c474e531ac92ec3774bde38979cccd7e20412e1144",
  "checkpoint_sha256": "3eaf4b77d7f7fa93b7df66633d6e1d31940e70231c8ea7c478794aa3fa444ef9",
  "data_sha256": "38dafc6a7a8bbf2e8e4666eca5bce5fcc2d7e06da7b2f8cb5321d12d98a7f700",
  "results_sha256": "acd95399ffcf7c3a5a2c3226a5e6e104d257a777d590741645463a4f02d2a727",
  "calculation_sha256": "db914789720f58ac9fc9649a655cb7ffc4c628393d9afc03fd3091dc8dda0acd",
  "verifier_sha256": "9f175670abb70f7819dd7f6d997ff0bef2e58df8dffd763b433f6c6cd62e332d",
  "next_step_decision_sha256": "9d93867fe4d16d46dd70810c929a0169fe9a013325f8c9e7b9221ba0c8cfb591",
  "replay_sha256": "f64119e3c3536cb3132f6eeac89b70887c126d3407eb0245c72f88098e2a73a6",
  "control_integrity_sha256": "9810807cb07b02f43f568f68bb82cb41a6eeff6799902254b4932e5c350ac838",
  "readme_sha256": "f00f1beb2bb1a99c52e779cf015b3ede1e12d28498c4969cfb59b1a037c05701",
  "assertions_passed": 86,
  "source_checks_passed": 16,
  "main_result": "E/J has eight primary500/100 labelled source squares. Across18 available context/mode tests, ten vertical E edges fail by25/23,2,or71/23 while every horizontal Shem J edge remains exact. Six Gear0 requests remain unavailable. No valid source mode is rejected.",
  "limits": "The test uses only existing regular Gear1–3 records. Conditional success does not select one valid historical binding over another; coordinate aliases and verification counts are not witnesses.",
  "canonical_or_graph_edits": false,
  "new_independent_agent_review": false,
  "review_provenance": "Root-agent analysis and deterministic replay; no new independent-agent review",
  "next_proposed_step": "Compose the admitted E/J squares across their complete two-edge regular source paths. Check whole-map equality, distinguish it from endpoint agreement of the other P/J words, and locate the actual Gear and E-iteration boundaries.",
  "next_step_executed": false
}