{
  "nodes": [
    2166,
    2051,
    1936
  ],
  "roles": [
    "regular Abraham birth",
    "proposed Isaac offering at age15",
    "cumulative Jacob death / Levi birth upper whole-year"
  ],
  "gaps": [
    115,
    115
  ],
  "carrier_change": 115,
  "claim": "source-appointed mixed-mode symmetry; offering age remains proposed"
}