{
  "passed": true,
  "method": "All nonempty subsets for column lengths 1..10, all unselected and selected Before/After anchors. Order-label equivariance makes separate ID permutations redundant for this reachability property.",
  "cases": 2036,
  "unselectedAnchors": 18324,
  "selectedAnchorRawNormalizationDivergences": 17004,
  "conclusion": "Every remainder gap is reachable via an unselected Before/After anchor. Selected-anchor no-op does not remove any possible changed result. Raw-gap and object-anchor policies remain distinct APIs; neither silently supersedes the other.",
  "counterexample": {
    "column": [
      "a",
      "b",
      "c",
      "d"
    ],
    "selected": [
      "b",
      "d"
    ],
    "drop": "Before d",
    "rawGapResult": [
      "a",
      "c",
      "b",
      "d"
    ],
    "objectAnchorResult": [
      "a",
      "b",
      "c",
      "d"
    ],
    "equivalentUnselectedDrop": "After c"
  }
}