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FA-18496 / Time representation / Open access

Holdover admission fabricates missing history or admits future sync · case 01

The decoded time state disagrees with the explicit regression oracle for history.

Verified by executionVariant 1 · 13 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Holdover admission fabricates missing history or admits future sync.

THE FAILURE

Holdover admission fabricates missing history or admits future sync.

Unsuccessful approach: The partial correction still substitutes r['has_sync'] at the same fault site.

Case contract

Clock quality state is determined from oscillator validity, acquisition lock count, elapsed time since last sync, max holdover, phase jump and lock threshold. Unknown oscillator is invalid; otherwise large phase jump requires reacquisition, recent sufficient lock is synchronized, old but bounded history is holdover, and missing/expired history is unsynchronized. Return usability and conservative uncertainty growth for holdover only.

Why this case matters

Clock transfer and timestamp consumers require preserved coordinate, phase, validity and elapsed-time semantics.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
from fractions import Fraction
N = 1
observations = []
def solve(r):
    age = r['now'] - r['last_sync']
    history = age >= 0
    jumped = abs(r['phase_jump']) > r['jump_limit']
    locked = r['lock_count'] >= r['required']
    recent = history and age <= r['fresh_window']
    holdover = history and age <= r['max_holdover']
    state = 'invalid' if not r['oscillator'] else ('acquire' if jumped else ('locked' if recent and locked else ('holdover' if holdover else 'unsynced')))
    growth = (age * r['drift'] + 999) // 1000 if state == 'holdover' else 0
    error = r['base_error'] + growth if state in ('locked','holdover') else None
    usable = state in ('locked','holdover') and error <= r['error_limit']
    return [state,error,usable]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 2}), ['locked', 2, True])
check('fixture 2', solve({'now': 105, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 3}), ['locked', 2, True])
check('fixture 3', solve({'now': 106, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 2}), ['holdover', 3, False])
check('fixture 4', solve({'now': 120, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['holdover', 4, True])
check('fixture 5', solve({'now': 121, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['unsynced', None, False])
check('fixture 6', solve({'now': 99, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['unsynced', None, False])
check('fixture 7', solve({'now': 100, 'last_sync': 100, 'has_sync': False, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['unsynced', None, False])
check('fixture 8', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': -6, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['acquire', None, False])
check('fixture 9', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 5, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['locked', 2, True])
check('fixture 10', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 1, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['holdover', 2, True])
check('fixture 11', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': False, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['invalid', None, False])
check('fixture 12', solve({'now': 110, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['holdover', 3, True])
variant = [({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 3, 'error_limit': 2}, ['locked', 3, False]), ({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 4, 'error_limit': 2}, ['locked', 4, False]), ({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 5, 'error_limit': 2}, ['locked', 5, False]), ({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 6, 'error_limit': 2}, ['locked', 6, False]), ({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 7, 'error_limit': 2}, ['locked', 7, False])]
check("variant capture", solve(variant[N-1][0]), variant[N-1][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
fixture 1['locked', 2, True]['locked', 2, True]Passed
fixture 2['locked', 2, True]['locked', 2, True]Passed
fixture 3['holdover', 3, False]['holdover', 3, False]Passed
fixture 4['holdover', 4, True]['holdover', 4, True]Passed
fixture 5['unsynced', None, False]['unsynced', None, False]Passed
fixture 6['unsynced', None, False]['unsynced', None, False]Passed
fixture 7['locked', 2, True]['unsynced', None, False]Failed
fixture 8['acquire', None, False]['acquire', None, False]Passed
fixture 9['locked', 2, True]['locked', 2, True]Passed
fixture 10['holdover', 2, True]['holdover', 2, True]Passed
fixture 11['invalid', None, False]['invalid', None, False]Passed
fixture 12['holdover', 3, True]['holdover', 3, True]Passed
variant capture['locked', 3, False]['locked', 3, False]Passed

SHA-256 / 71f95d217603a614c4103bd4fbeedfe943c8c08a94e528c4e29d0afb62d3bcec

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
from fractions import Fraction
N = 1
observations = []
def solve(r):
    age = r['now'] - r['last_sync']
    history = r['has_sync']
    jumped = abs(r['phase_jump']) > r['jump_limit']
    locked = r['lock_count'] >= r['required']
    recent = history and age <= r['fresh_window']
    holdover = history and age <= r['max_holdover']
    state = 'invalid' if not r['oscillator'] else ('acquire' if jumped else ('locked' if recent and locked else ('holdover' if holdover else 'unsynced')))
    growth = (age * r['drift'] + 999) // 1000 if state == 'holdover' else 0
    error = r['base_error'] + growth if state in ('locked','holdover') else None
    usable = state in ('locked','holdover') and error <= r['error_limit']
    return [state,error,usable]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 2}), ['locked', 2, True])
check('fixture 2', solve({'now': 105, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 3}), ['locked', 2, True])
check('fixture 3', solve({'now': 106, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 2}), ['holdover', 3, False])
check('fixture 4', solve({'now': 120, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['holdover', 4, True])
check('fixture 5', solve({'now': 121, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['unsynced', None, False])
check('fixture 6', solve({'now': 99, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['unsynced', None, False])
check('fixture 7', solve({'now': 100, 'last_sync': 100, 'has_sync': False, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['unsynced', None, False])
check('fixture 8', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': -6, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['acquire', None, False])
check('fixture 9', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 5, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['locked', 2, True])
check('fixture 10', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 1, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['holdover', 2, True])
check('fixture 11', solve({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': False, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['invalid', None, False])
check('fixture 12', solve({'now': 110, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 2, 'error_limit': 5}), ['holdover', 3, True])
variant = [({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 3, 'error_limit': 2}, ['locked', 3, False]), ({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 4, 'error_limit': 2}, ['locked', 4, False]), ({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 5, 'error_limit': 2}, ['locked', 5, False]), ({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 6, 'error_limit': 2}, ['locked', 6, False]), ({'now': 100, 'last_sync': 100, 'has_sync': True, 'phase_jump': 0, 'jump_limit': 5, 'lock_count': 3, 'required': 3, 'fresh_window': 5, 'max_holdover': 20, 'oscillator': True, 'drift': 100, 'base_error': 7, 'error_limit': 2}, ['locked', 7, False])]
check("variant capture", solve(variant[N-1][0]), variant[N-1][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
fixture 1['locked', 2, True]['locked', 2, True]Passed
fixture 2['locked', 2, True]['locked', 2, True]Passed
fixture 3['holdover', 3, False]['holdover', 3, False]Passed
fixture 4['holdover', 4, True]['holdover', 4, True]Passed
fixture 5['unsynced', None, False]['unsynced', None, False]Passed
fixture 6['locked', 2, True]['unsynced', None, False]Failed
fixture 7['unsynced', None, False]['unsynced', None, False]Passed
fixture 8['acquire', None, False]['acquire', None, False]Passed
fixture 9['locked', 2, True]['locked', 2, True]Passed
fixture 10['holdover', 2, True]['holdover', 2, True]Passed
fixture 11['invalid', None, False]['invalid', None, False]Passed
fixture 12['holdover', 3, True]['holdover', 3, True]Passed
variant capture['locked', 3, False]['locked', 3, False]Passed

SHA-256 / 23c9ef8f45d8cf60c26d86063a34625595182791cf38cc7d888555a8729f80d5

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

This mechanism has 13 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

Deterministic integer reference model with stipulated units and policies; not a complete clock, wire standard or platform implementation. 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 2026-09-29T14:39:58.580228+00:00.

Case digest / cf8e3fd6d5b7fa3bcdf1509389c84edbc25550234404c1431a1fc92013c9790d