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FA-41096 / Heap invariants / Open access

Replacement selection ends a run only when no active replacement remains · case 01

The bounded replacement selection certificate reports an incorrect run ended.

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

ROOT CAUSE

Replacement selection ends a run only when no active replacement remains.

THE FAILURE

Replacement selection ends a run only when no active replacement remains.

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

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.

1 / The failure

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

N = 1
observations = []
def solve(d):
    last=d['last']; a=d['arrivals']; active=[x for x in a if x[1]>=last]; frozen=[x for x in a if x[1]<last]
    return {'active': [x[0] for x in active],
    'frozen': [x[0] for x in frozen],
    'active_order': [x[0] for x in sorted(active,key=lambda x:x[1])],
    'frozen_order': [x[0] for x in sorted(frozen,key=lambda x:x[1])],
    'next': min((x[1] for x in active),default=None),
    'run_ended': not a}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})], [({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 6, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})], [({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 7, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})], [({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})], [({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 9, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})]][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{'active': [], 'active_order': [], 'frozen': [], 'frozen_order': [], 'next': None, 'run_ended': True}{'active': [], 'active_order': [], 'frozen': [], 'frozen_order': [], 'next': None, 'run_ended': True}Passed
regression certificate 2{'active': ['a'], 'active_order': ['a'], 'frozen': [], 'frozen_order': [], 'next': 3, 'run_ended': False}{'active': ['a'], 'active_order': ['a'], 'frozen': [], 'frozen_order': [], 'next': 3, 'run_ended': False}Passed
regression certificate 3{'active': ['a', 'c', 'e'], 'active_order': ['c', 'e', 'a'], 'frozen': ['b', 'd'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}{'active': ['a', 'c', 'e'], 'active_order': ['c', 'e', 'a'], 'frozen': ['b', 'd'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}Passed
regression certificate 4{'active': [], 'active_order': [], 'frozen': ['a', 'b', 'c'], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': False}{'active': [], 'active_order': [], 'frozen': ['a', 'b', 'c'], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}Failed
regression certificate 5{'active': ['a', 'b', 'c'], 'active_order': ['b', 'c', 'a'], 'frozen': [], 'frozen_order': [], 'next': 1, 'run_ended': False}{'active': ['a', 'b', 'c'], 'active_order': ['b', 'c', 'a'], 'frozen': [], 'frozen_order': [], 'next': 1, 'run_ended': False}Passed
regression certificate 6{'active': ['a', 'b'], 'active_order': ['a', 'b'], 'frozen': ['c'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}{'active': ['a', 'b'], 'active_order': ['a', 'b'], 'frozen': ['c'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}Passed
variant-dependent certificate{'active': [], 'active_order': [], 'frozen': ['a', 'b', 'c'], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': False}{'active': [], 'active_order': [], 'frozen': ['a', 'b', 'c'], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True}Failed

SHA-256 / 61bf745963696463294907498962de85fb72322378f1c626b1d2c61490b8a8b9

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(d):
    last=d['last']; a=d['arrivals']; active=[x for x in a if x[1]>=last]; frozen=[x for x in a if x[1]<last]
    return {'active': [x[0] for x in active],
    'frozen': [x[0] for x in frozen],
    'active_order': [x[0] for x in sorted(active,key=lambda x:x[1])],
    'frozen_order': [x[0] for x in sorted(frozen,key=lambda x:x[1])],
    'next': min((x[1] for x in active),default=None),
    'run_ended': bool(frozen)}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})], [({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 6, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})], [({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 7, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})], [({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})], [({'last': 3, 'arrivals': []}, {'active': [], 'frozen': [], 'active_order': [], 'frozen_order': [], 'next': None, 'run_ended': True}), ({'last': 3, 'arrivals': [['a', 3]]}, {'active': ['a'], 'frozen': [], 'active_order': ['a'], 'frozen_order': [], 'next': 3, 'run_ended': False}), ({'last': 5, 'arrivals': [['a', 7], ['b', 2], ['c', 5], ['d', 1], ['e', 6]]}, {'active': ['a', 'c', 'e'], 'frozen': ['b', 'd'], 'active_order': ['c', 'e', 'a'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}), ({'last': 8, 'arrivals': [['a', 4], ['b', 2], ['c', 6]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}), ({'last': 0, 'arrivals': [['a', 3], ['b', 1], ['c', 2]]}, {'active': ['a', 'b', 'c'], 'frozen': [], 'active_order': ['b', 'c', 'a'], 'frozen_order': [], 'next': 1, 'run_ended': False}), ({'last': 4, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': ['a', 'b'], 'frozen': ['c'], 'active_order': ['a', 'b'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}), ({'last': 9, 'arrivals': [['a', 4], ['b', 4], ['c', 3]]}, {'active': [], 'frozen': ['a', 'b', 'c'], 'active_order': [], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True})]][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{'active': [], 'active_order': [], 'frozen': [], 'frozen_order': [], 'next': None, 'run_ended': False}{'active': [], 'active_order': [], 'frozen': [], 'frozen_order': [], 'next': None, 'run_ended': True}Failed
regression certificate 2{'active': ['a'], 'active_order': ['a'], 'frozen': [], 'frozen_order': [], 'next': 3, 'run_ended': False}{'active': ['a'], 'active_order': ['a'], 'frozen': [], 'frozen_order': [], 'next': 3, 'run_ended': False}Passed
regression certificate 3{'active': ['a', 'c', 'e'], 'active_order': ['c', 'e', 'a'], 'frozen': ['b', 'd'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': True}{'active': ['a', 'c', 'e'], 'active_order': ['c', 'e', 'a'], 'frozen': ['b', 'd'], 'frozen_order': ['d', 'b'], 'next': 5, 'run_ended': False}Failed
regression certificate 4{'active': [], 'active_order': [], 'frozen': ['a', 'b', 'c'], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}{'active': [], 'active_order': [], 'frozen': ['a', 'b', 'c'], 'frozen_order': ['b', 'a', 'c'], 'next': None, 'run_ended': True}Passed
regression certificate 5{'active': ['a', 'b', 'c'], 'active_order': ['b', 'c', 'a'], 'frozen': [], 'frozen_order': [], 'next': 1, 'run_ended': False}{'active': ['a', 'b', 'c'], 'active_order': ['b', 'c', 'a'], 'frozen': [], 'frozen_order': [], 'next': 1, 'run_ended': False}Passed
regression certificate 6{'active': ['a', 'b'], 'active_order': ['a', 'b'], 'frozen': ['c'], 'frozen_order': ['c'], 'next': 4, 'run_ended': True}{'active': ['a', 'b'], 'active_order': ['a', 'b'], 'frozen': ['c'], 'frozen_order': ['c'], 'next': 4, 'run_ended': False}Failed
variant-dependent certificate{'active': [], 'active_order': [], 'frozen': ['a', 'b', 'c'], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True}{'active': [], 'active_order': [], 'frozen': ['a', 'b', 'c'], 'frozen_order': ['c', 'a', 'b'], 'next': None, 'run_ended': True}Passed

SHA-256 / c27f0b061095346c08e203048d62255caef974bb63d027c57478f3a941ee5341

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

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.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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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 2026-09-29T14:43:37.561628+00:00.

Case digest / d4d7690af03dc67433042614931df5bd505c5ae5175fbdad3259d1aa6eabe1e8