FA-40117 / Heap invariants / Member archive

Fibonacci cascade never marks a root · case 02

The bounded fibonacci cascade certificate reports an incorrect new mark.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

A cascading-cut path runs from the parent of an initially cut node upward as [id,is_root,marked]. Stop at a root or first unmarked nonroot; mark that first unmarked node. Previously marked nonroots are cut and unmarked. Report cut ids, marked stop, cleared ids, visited count, promoted count, and potential change roots+2*marks.

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 2	`{"cleared": [], "cuts": [], "new_mark": 1, "potential_delta": 0, "promoted_count": 0, "visits": 1}`	`{"cleared": [], "cuts": [], "new_mark": null, "potential_delta": 0, "promoted_count": 0, "visits": 1}`	Failed

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