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FA-40331 / Heap invariants / Open access

Lazy heap stale-discard accounting excludes the delivered live record · case 01

The bounded lazy pop certificate reports an incorrect discarded.

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

ROOT CAUSE

Lazy heap stale-discard accounting excludes the delivered live record.

VERIFIED REPAIR

Derive discarded using len(q) if j is None else j under the stated bounded certificate contract.

Unsuccessful approach: The local patch uses len(q) if j is None else j+1 and still violates the stated relation.

Case contract

Physical lazy-heap records [priority,serial,id,version] are already sorted lexicographically by priority then serial. Live map id->[version,payload]. Skip missing or version-stale records, pop the first current record, delete its live-map id, and retain the remaining physical suffix. No unindexed priority changes are allowed.

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']; valid=[i for i,x in enumerate(q) if x[2] in live and live[x[2]][0]==x[3]]; j=valid[0] if valid else None
    return {'selected': None if j is None else q[j][2],
    'payload': None if j is None else live[q[j][2]][1],
    'discarded': 0,
    'suffix': [] if j is None else q[j+1:],
    'live_after': {k:v for k,v in live.items() if j is None or k!=q[j][2]},
    'empty': j is None}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -1, 'stale1', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 1, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -2, 'stale2', 0], [0, -2, 'stale2', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 2, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -3, 'stale3', 0], [0, -3, 'stale3', 0], [0, -3, 'stale3', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 3, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 4, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 5, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': 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{'discarded': 0, 'empty': True, 'live_after': {}, 'payload': None, 'selected': None, 'suffix': []}{'discarded': 0, 'empty': True, 'live_after': {}, 'payload': None, 'selected': None, 'suffix': []}Passed
regression certificate 2{'discarded': 0, 'empty': False, 'live_after': {}, 'payload': 'A', 'selected': 'a', 'suffix': []}{'discarded': 0, 'empty': False, 'live_after': {}, 'payload': 'A', 'selected': 'a', 'suffix': []}Passed
regression certificate 3{'discarded': 0, 'empty': False, 'live_after': {'b': [0, 'B']}, 'payload': 'new', 'selected': 'a', 'suffix': [[3, 2, 'b', 0]]}{'discarded': 1, 'empty': False, 'live_after': {'b': [0, 'B']}, 'payload': 'new', 'selected': 'a', 'suffix': [[3, 2, 'b', 0]]}Failed
regression certificate 4{'discarded': 0, 'empty': False, 'live_after': {}, 'payload': 'B', 'selected': 'b', 'suffix': []}{'discarded': 1, 'empty': False, 'live_after': {}, 'payload': 'B', 'selected': 'b', 'suffix': []}Failed
regression certificate 5{'discarded': 0, 'empty': True, 'live_after': {'a': [2, 'A']}, 'payload': None, 'selected': None, 'suffix': []}{'discarded': 1, 'empty': True, 'live_after': {'a': [2, 'A']}, 'payload': None, 'selected': None, 'suffix': []}Failed
regression certificate 6{'discarded': 0, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}{'discarded': 0, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}Passed
variant-dependent certificate{'discarded': 0, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}{'discarded': 1, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}Failed

SHA-256 / 67b28e33502b1317bf7f336382eff7051c1e64b090c41173a343195b242ec534

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']; valid=[i for i,x in enumerate(q) if x[2] in live and live[x[2]][0]==x[3]]; j=valid[0] if valid else None
    return {'selected': None if j is None else q[j][2],
    'payload': None if j is None else live[q[j][2]][1],
    'discarded': len(q) if j is None else j+1,
    'suffix': [] if j is None else q[j+1:],
    'live_after': {k:v for k,v in live.items() if j is None or k!=q[j][2]},
    'empty': j is None}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -1, 'stale1', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 1, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -2, 'stale2', 0], [0, -2, 'stale2', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 2, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -3, 'stale3', 0], [0, -3, 'stale3', 0], [0, -3, 'stale3', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 3, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 4, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 5, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': 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{'discarded': 0, 'empty': True, 'live_after': {}, 'payload': None, 'selected': None, 'suffix': []}{'discarded': 0, 'empty': True, 'live_after': {}, 'payload': None, 'selected': None, 'suffix': []}Passed
regression certificate 2{'discarded': 1, 'empty': False, 'live_after': {}, 'payload': 'A', 'selected': 'a', 'suffix': []}{'discarded': 0, 'empty': False, 'live_after': {}, 'payload': 'A', 'selected': 'a', 'suffix': []}Failed
regression certificate 3{'discarded': 2, 'empty': False, 'live_after': {'b': [0, 'B']}, 'payload': 'new', 'selected': 'a', 'suffix': [[3, 2, 'b', 0]]}{'discarded': 1, 'empty': False, 'live_after': {'b': [0, 'B']}, 'payload': 'new', 'selected': 'a', 'suffix': [[3, 2, 'b', 0]]}Failed
regression certificate 4{'discarded': 2, 'empty': False, 'live_after': {}, 'payload': 'B', 'selected': 'b', 'suffix': []}{'discarded': 1, 'empty': False, 'live_after': {}, 'payload': 'B', 'selected': 'b', 'suffix': []}Failed
regression certificate 5{'discarded': 1, 'empty': True, 'live_after': {'a': [2, 'A']}, 'payload': None, 'selected': None, 'suffix': []}{'discarded': 1, 'empty': True, 'live_after': {'a': [2, 'A']}, 'payload': None, 'selected': None, 'suffix': []}Passed
regression certificate 6{'discarded': 1, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}{'discarded': 0, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}Failed
variant-dependent certificate{'discarded': 2, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}{'discarded': 1, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}Failed

SHA-256 / cfcfd99cf9cd049a2f7e3541a330f94dc2a6a45ddb57b2b37ce8b572fa464961

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    q=d['records']; live=d['live']; valid=[i for i,x in enumerate(q) if x[2] in live and live[x[2]][0]==x[3]]; j=valid[0] if valid else None
    return {'selected': None if j is None else q[j][2],
    'payload': None if j is None else live[q[j][2]][1],
    'discarded': len(q) if j is None else j,
    'suffix': [] if j is None else q[j+1:],
    'live_after': {k:v for k,v in live.items() if j is None or k!=q[j][2]},
    'empty': j is None}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -1, 'stale1', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 1, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -2, 'stale2', 0], [0, -2, 'stale2', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 2, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -3, 'stale3', 0], [0, -3, 'stale3', 0], [0, -3, 'stale3', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 3, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [0, -4, 'stale4', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 4, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False})], [({'records': [], 'live': {}}, {'selected': None, 'payload': None, 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': True}), ({'records': [[1, 0, 'a', 0]], 'live': {'a': [0, 'A']}}, {'selected': 'a', 'payload': 'A', 'discarded': 0, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 0], [2, 1, 'a', 1], [3, 2, 'b', 0]], 'live': {'a': [1, 'new'], 'b': [0, 'B']}}, {'selected': 'a', 'payload': 'new', 'discarded': 1, 'suffix': [[3, 2, 'b', 0]], 'live_after': {'b': [0, 'B']}, 'empty': False}), ({'records': [[0, 0, 'x', 2], [1, 1, 'b', 0]], 'live': {'b': [0, 'B']}}, {'selected': 'b', 'payload': 'B', 'discarded': 1, 'suffix': [], 'live_after': {}, 'empty': False}), ({'records': [[1, 0, 'a', 1]], 'live': {'a': [2, 'A']}}, {'selected': None, 'payload': None, 'discarded': 1, 'suffix': [], 'live_after': {'a': [2, 'A']}, 'empty': True}), ({'records': [[1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 0, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': False}), ({'records': [[0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [0, -5, 'stale5', 0], [1, 0, 'c', 0], [1, 1, 'b', 0], [2, 2, 'a', 1]], 'live': {'a': [1, 'A'], 'b': [0, 'B'], 'c': [0, 'C']}}, {'selected': 'c', 'payload': 'C', 'discarded': 5, 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]], 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'empty': 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{'discarded': 0, 'empty': True, 'live_after': {}, 'payload': None, 'selected': None, 'suffix': []}{'discarded': 0, 'empty': True, 'live_after': {}, 'payload': None, 'selected': None, 'suffix': []}Passed
regression certificate 2{'discarded': 0, 'empty': False, 'live_after': {}, 'payload': 'A', 'selected': 'a', 'suffix': []}{'discarded': 0, 'empty': False, 'live_after': {}, 'payload': 'A', 'selected': 'a', 'suffix': []}Passed
regression certificate 3{'discarded': 1, 'empty': False, 'live_after': {'b': [0, 'B']}, 'payload': 'new', 'selected': 'a', 'suffix': [[3, 2, 'b', 0]]}{'discarded': 1, 'empty': False, 'live_after': {'b': [0, 'B']}, 'payload': 'new', 'selected': 'a', 'suffix': [[3, 2, 'b', 0]]}Passed
regression certificate 4{'discarded': 1, 'empty': False, 'live_after': {}, 'payload': 'B', 'selected': 'b', 'suffix': []}{'discarded': 1, 'empty': False, 'live_after': {}, 'payload': 'B', 'selected': 'b', 'suffix': []}Passed
regression certificate 5{'discarded': 1, 'empty': True, 'live_after': {'a': [2, 'A']}, 'payload': None, 'selected': None, 'suffix': []}{'discarded': 1, 'empty': True, 'live_after': {'a': [2, 'A']}, 'payload': None, 'selected': None, 'suffix': []}Passed
regression certificate 6{'discarded': 0, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}{'discarded': 0, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}Passed
variant-dependent certificate{'discarded': 1, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}{'discarded': 1, 'empty': False, 'live_after': {'a': [1, 'A'], 'b': [0, 'B']}, 'payload': 'C', 'selected': 'c', 'suffix': [[1, 1, 'b', 0], [2, 2, 'a', 1]]}Passed

SHA-256 / 453d099a94410587d88cd566df2b82733d9fe2e8487109462fdff3d0cdba5e9e

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 2026-09-29T14:43:30.077054+00:00.

Case digest / 21d24ccfc069d48e5f49eee8f52c1f17432d27a883f6d48930513115405e9706