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FA-40356 / Heap invariants / Open access

Lazy compaction counts obsolete physical records rather than logical size difference · case 01

The bounded lazy compaction certificate reports an incorrect stale.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Lazy compaction counts obsolete physical records rather than logical size difference.

THE FAILURE

Lazy compaction counts obsolete physical records rather than logical size difference.

Unsuccessful approach: The local patch uses len(kept) and still violates the stated relation.

Case contract

A lazy heap compaction receives arbitrary physical records [priority,serial,id,version] and live map id->version. Preserve only records whose id and version match, retain duplicate physical records for diagnostic detection, heapify by (priority,serial), and report stale count, duplicate-current ids, live-id coverage, storage ratio numerator, and triggering condition physical>2*live+slack.

Why this case matters

This isolates an internal heap representation or priority-structure invariant using deterministic finite records.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    q=d['records']; live=d['live']; kept=[x for x in q if x[2] in live and x[3]==live[x[2]]]
    return {'kept': sorted(kept,key=lambda x:(x[0],x[1])),
    'stale': len(q)-len(live),
    'duplicate_current': sorted({x[2] for x in kept if sum(y[2]==x[2] for y in kept)>1}),
    'missing': sorted(set(live)-{x[2] for x in kept}),
    'post_size': len(kept),
    'trigger': len(q)>2*len(live)+d["slack"]}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})], [({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 3}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})], [({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 4}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})], [({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 5}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})], [({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 6}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})]][N-1]
check('regression certificate 1', solve(cases[0][0]), cases[0][1])
check('regression certificate 2', solve(cases[1][0]), cases[1][1])
check('regression certificate 3', solve(cases[2][0]), cases[2][1])
check('regression certificate 4', solve(cases[3][0]), cases[3][1])
check('regression certificate 5', solve(cases[4][0]), cases[4][1])
check('regression certificate 6', solve(cases[5][0]), cases[5][1])
check('variant-dependent certificate', solve(cases[6][0]), cases[6][1])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression certificate 1{'duplicate_current': [], 'kept': [], 'missing': [], 'post_size': 0, 'stale': 0, 'trigger': False}{'duplicate_current': [], 'kept': [], 'missing': [], 'post_size': 0, 'stale': 0, 'trigger': False}Passed
regression certificate 2{'duplicate_current': [], 'kept': [[1, 0, 'a', 0]], 'missing': [], 'post_size': 1, 'stale': 0, 'trigger': False}{'duplicate_current': [], 'kept': [[1, 0, 'a', 0]], 'missing': [], 'post_size': 1, 'stale': 0, 'trigger': False}Passed
regression certificate 3{'duplicate_current': [], 'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'missing': [], 'post_size': 2, 'stale': 1, 'trigger': False}{'duplicate_current': [], 'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'missing': [], 'post_size': 2, 'stale': 1, 'trigger': False}Passed
regression certificate 4{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 1, 'trigger': False}{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 2, 'trigger': False}Failed
regression certificate 5{'duplicate_current': ['a'], 'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'missing': [], 'post_size': 2, 'stale': 3, 'trigger': False}{'duplicate_current': ['a'], 'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'missing': [], 'post_size': 2, 'stale': 2, 'trigger': False}Failed
regression certificate 6{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 3, 'trigger': True}{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 4, 'trigger': True}Failed
variant-dependent certificate{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 3, 'trigger': False}{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 4, 'trigger': False}Failed

SHA-256 / c7605967dd8869cada8a2e36023fc467fc056f234652bf7f3555a2aad14d8da3

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    q=d['records']; live=d['live']; kept=[x for x in q if x[2] in live and x[3]==live[x[2]]]
    return {'kept': sorted(kept,key=lambda x:(x[0],x[1])),
    'stale': len(kept),
    'duplicate_current': sorted({x[2] for x in kept if sum(y[2]==x[2] for y in kept)>1}),
    'missing': sorted(set(live)-{x[2] for x in kept}),
    'post_size': len(kept),
    'trigger': len(q)>2*len(live)+d["slack"]}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})], [({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 3}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})], [({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 4}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})], [({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 5}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})], [({'records': [], 'live': {}, 'slack': 0}, {'kept': [], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 0, 'trigger': False}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': 0}, 'slack': 0}, {'kept': [[1, 0, 'a', 0]], 'stale': 0, 'duplicate_current': [], 'missing': [], 'post_size': 1, 'trigger': False}), ({'records': [[5, 0, 'a', 0], [3, 1, 'a', 1], [2, 2, 'b', 0]], 'live': {'a': 1, 'b': 0}, 'slack': 0}, {'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'stale': 1, 'duplicate_current': [], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1]], 'live': {'a': 2}, 'slack': 0}, {'kept': [], 'stale': 2, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False}), ({'records': [[2, 0, 'a', 1], [1, 1, 'a', 1], [3, 2, 'x', 0], [4, 3, 'y', 0]], 'live': {'a': 1}, 'slack': 2}, {'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'stale': 2, 'duplicate_current': ['a'], 'missing': [], 'post_size': 2, 'trigger': False}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 1}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': True}), ({'records': [[0, 0, 'x', 0], [1, 1, 'x', 0], [2, 2, 'x', 0], [3, 3, 'x', 0]], 'live': {'a': 1}, 'slack': 6}, {'kept': [], 'stale': 4, 'duplicate_current': [], 'missing': ['a'], 'post_size': 0, 'trigger': False})]][N-1]
check('regression certificate 1', solve(cases[0][0]), cases[0][1])
check('regression certificate 2', solve(cases[1][0]), cases[1][1])
check('regression certificate 3', solve(cases[2][0]), cases[2][1])
check('regression certificate 4', solve(cases[3][0]), cases[3][1])
check('regression certificate 5', solve(cases[4][0]), cases[4][1])
check('regression certificate 6', solve(cases[5][0]), cases[5][1])
check('variant-dependent certificate', solve(cases[6][0]), cases[6][1])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression certificate 1{'duplicate_current': [], 'kept': [], 'missing': [], 'post_size': 0, 'stale': 0, 'trigger': False}{'duplicate_current': [], 'kept': [], 'missing': [], 'post_size': 0, 'stale': 0, 'trigger': False}Passed
regression certificate 2{'duplicate_current': [], 'kept': [[1, 0, 'a', 0]], 'missing': [], 'post_size': 1, 'stale': 1, 'trigger': False}{'duplicate_current': [], 'kept': [[1, 0, 'a', 0]], 'missing': [], 'post_size': 1, 'stale': 0, 'trigger': False}Failed
regression certificate 3{'duplicate_current': [], 'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'missing': [], 'post_size': 2, 'stale': 2, 'trigger': False}{'duplicate_current': [], 'kept': [[2, 2, 'b', 0], [3, 1, 'a', 1]], 'missing': [], 'post_size': 2, 'stale': 1, 'trigger': False}Failed
regression certificate 4{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 0, 'trigger': False}{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 2, 'trigger': False}Failed
regression certificate 5{'duplicate_current': ['a'], 'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'missing': [], 'post_size': 2, 'stale': 2, 'trigger': False}{'duplicate_current': ['a'], 'kept': [[1, 1, 'a', 1], [2, 0, 'a', 1]], 'missing': [], 'post_size': 2, 'stale': 2, 'trigger': False}Passed
regression certificate 6{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 0, 'trigger': True}{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 4, 'trigger': True}Failed
variant-dependent certificate{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 0, 'trigger': False}{'duplicate_current': [], 'kept': [], 'missing': ['a'], 'post_size': 0, 'stale': 4, 'trigger': False}Failed

SHA-256 / 3d9e07be56fd25e1fda02e5ecef9ff5156a5735442aeb22579eaa9d1d40d6021

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This mechanism has 7 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

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Verification & scope

A stipulated offline diagnostic model; it does not implement a production allocator, concurrency protocol, or complete heap library. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:43:30.526235+00:00.

Case digest / 3fa0b6703fb7b144172072c77b7c4530a2ae2bb04850452b09db48be7fe0336e