{
  "input": "sourceD, declaredanchorA, originalspanD\u2212A",
  "register": [
    "trailing-zero count",
    "core length",
    "ordered core digits"
  ],
  "evaluation": "A+I(D\u2212A)=D+g(D\u2212A)",
  "paired_constraint": "1400 anchor change acts through borrow/length/zero strata",
  "comparison_with_rounding": "both have explicit output-minus-input fields; their operators and admitted subdivisions differ",
  "unexplained": "why the source chronology has these original digit values"
}