{
  "number": 399,
  "date": "2026-09-24",
  "title": "Complete inverse-E closure test of common P/J source edges",
  "question": "Which of all ten common P/J coordinate edges has a source-admitted E return pivot?",
  "authorization": "User authorized next10 bounded steps C394–C403; next question reassessed after each completed result.",
  "scope": "Mirror/529; regular Gears Noah/Shem/Flood only; SP companion local. Fixed source inputs, no canonical/graph changes."
}