FA-40243 / Heap invariants / Member archive

Radix redistribution collects every equal-minimum key into bucket zero · case 03

The bounded radix redistribute certificate reports an incorrect zero ids.

Member previewVariant 3 · 3 implementations · 7 checks per implementation

Case contract

Redistribute one nonempty radix bucket with entries [id,key], all keys at least old_last. Set new_last to bucket minimum and move every entry to bit_length(key XOR new_last); preserve entry order within each destination bucket. Report threshold, assignments, bucket-zero ids, moved count, old-bucket clearing, and maximum destination.

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	`{"destinations": [[1, 2], [2, 0], [3, 2]], "largest_destination": 2, "moved": 3, "source_after": [], "threshold": 4, "zero_ids": [1]}`	`{"destinations": [[1, 2], [2, 0], [3, 2]], "largest_destination": 2, "moved": 3, "source_after": [], "threshold": 4, "zero_ids": [2]}`	Failed

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

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