FA-41092 / Heap invariants / Member archive

Replacement selection has no current candidate when every replacement is frozen · case 02

The bounded replacement selection certificate reports an incorrect next.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

A replacement-selection external-sort heap receives last emitted key and new records [id,key]. Keys >=last remain active for current run; smaller keys freeze for next run. Return active ids, frozen ids, active sorted order, frozen sorted order, next current-run key, and end-run flag. Equal keys stay active.

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	`{"active": ["a", "c", "e"], "active_order": ["c", "e", "a"], "frozen": ["b", "d"], "frozen_order": ["d", "b"], "next": 1, "run_ended": false}`	`{"active": ["a", "c", "e"], "active_order": ["c", "e", "a"], "frozen": ["b", "d"], "frozen_order": ["d", "b"], "next": 5, "run_ended": false}`	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.