FA-40770 / Heap invariants / Member archive

Min-max cross-level correction conserves duplicate keys across all three nodes · case 05

The bounded minmax grandchild step certificate reports an incorrect multiset.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

A minimum-level trickle step receives current key x, chosen grandchild key g, its parent key p, and ids. After swapping x with smaller g, x at the grandchild must also be no greater than its maximum-level parent; if x>p exchange those two. Return root key, grandchild key, parent key, cross-level correction flag, two-step trace, and preserved multiset.

Why this case matters

This isolates an internal heap representation or priority-structure invariant using deterministic finite records.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression certificate 3	`{"correction": false, "grandchild_key": 4, "multiset": [3, 3, 8], "parent_key": 8, "root_key": 3, "trace": []}`	`{"correction": false, "grandchild_key": 4, "multiset": [3, 4, 8], "parent_key": 8, "root_key": 3, "trace": []}`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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