FA-40830 / Heap invariants / Member archive

Indexed erase shrinks logical size exactly once even for tail deletion · case 05

The bounded indexed erase routing certificate reports an incorrect size.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

An indexed heap erasure certificate gives slots [id,key], selected slot i, and a valid min-heap prefix before deletion. Fill the hole with the last record unless erasing the tail. Decide upward repair if replacement is smaller than its parent, otherwise downward; return shortened slots, removed id, direction, replacement handle location, retained identities, and logical size.

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 1	`{"direction": "none", "removed": "a", "replacement_location": null, "retained": [], "size": 1, "slots": []}`	`{"direction": "none", "removed": "a", "replacement_location": null, "retained": [], "size": 0, "slots": []}`	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.