FA-39972 / Heap invariants / Member archive

Radix zero bucket accepts all keys below the next power of two · case 02

The bounded radix buckets certificate reports an incorrect zero members.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

A monotone integer radix-heap certificate has nonnegative last, entries [key,id,bucket], and width. Bucket index is bit_length(key XOR last). Report monotonicity violations, bucket assignment violations, zero-bucket members, next nonempty bucket, next extraction threshold, and overflow keys. This is an unsigned bounded toy representation.

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 4	`{"monotone": [], "new_last": 4, "next_bucket": 1, "overflow": [], "placement": ["c"], "zero_members": ["b", "c"]}`	`{"monotone": [], "new_last": 4, "next_bucket": 1, "overflow": [], "placement": ["c"], "zero_members": ["c"]}`	Failed

MEMBER ARCHIVE

The complete case is available to members.

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

Member access is invitation-based. Sign in with your invited account to inspect the sources.