{
  "completed_step": "C358",
  "next_proposed_step": "C359",
  "question": "Test the source realization of the two-segment comparison460+598→500+600: apply E to the Noah-to-MT-Noah leg and300/299 to the following598 gap, keeping the join continuous and checking the resulting SP Shem birth/death endpoints.",
  "reason_selected_after_current_result": "The failed endpoint identification reveals the exact two-year distinction. The original partition and the established two ratios now give a concrete, finite source-endpoint construction to test.",
  "executed": false,
  "authorization_remaining": 5,
  "fixed_scope": "Mirror/529; regular Gears Noah/Shem/Flood only; SP companion local. Fixed source inputs, no canonical/graph changes."
}