{
  "completed_step": "C336",
  "next_proposed_step": "C337",
  "question": "Factor the existing left and right2K conditions into their source selectors. Derive necessary and sufficient conditions within the already frozen cumulative ON/OFF and regular Cainan/Terah/Gear/rail domains; reconcile the factorization with C287 rather than repeating its census.",
  "reason_selected_after_current_result": "C336 shows exactly which held partners create each shortened span. A source-labelled factorization can reveal which choices 2K actually determines and which coupling remains additional.",
  "executed": false,
  "authorization_remaining": 7,
  "fixed_scope": "Mirror/529; regular Gears Noah/Shem/Flood only; SP companion local. Fixed source inputs, no canonical/graph changes."
}