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FA-18096 / Time representation / Open access

Clock bridge applies calibration from another rate generation · case 01

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

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

ROOT CAUSE

Clock bridge applies calibration from another rate generation.

THE FAILURE

Clock bridge applies calibration from another rate generation.

Unsuccessful approach: The partial correction still substitutes True at the same fault site.

Case contract

Bridge two clock domains through one synchronization pair and exact positive rational rate p/q. A reading carries boot identity and calibration generation; reject stale identity, expiration, or unsupported extrapolation. Outputs admission, mapped rational coordinate, nearest interval endpoints expanded by calibration error, and remaining certificate age. Ages are monotonic and nonnegative. Negative target-domain calibration error is malformed; zero is a valid exact bound.

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):
    boot_ok = r['boot'] == r['cal_boot']
    generation_ok = r['generation'] >= r['cal_generation']
    age = r['now'] - r['cal_time']
    fresh = 0 <= age < r['ttl']
    delta = r['reading'] - r['source_anchor']
    supported = abs(delta) <= r['radius']
    coordinate = Fraction(delta * r['p'],r['q']) + r['target_anchor']
    low = coordinate - r['error']
    high = coordinate + r['error']
    accepted = boot_ok and generation_ok and fresh and supported and r['error'] >= 0
    return [accepted, str(coordinate) if accepted else None, [str(low),str(high)] if accepted else None,max(0,r['ttl']-age)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [True, '503', ['501', '505'], 8])
check('fixture 2', solve({'boot': 'b', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 3', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 3, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 4', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 1, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 5', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 9, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 11])
check('fixture 6', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 20, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 0])
check('fixture 7', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 19, 'cal_time': 10, 'ttl': 10, 'reading': 110, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [True, '515', ['513', '517'], 1])
check('fixture 8', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 89, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 9', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 111, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 10', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 10, 'cal_time': 10, 'ttl': 10, 'reading': 90, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [True, '485', ['483', '487'], 10])
check('fixture 11', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': -1}), [False, None, None, 8])
check('fixture 12', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 0}), [True, '503', ['503', '503'], 8])
variant = [({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 103, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '1009/2', ['1005/2', '1013/2'], 8]), ({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 104, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '506', ['504', '508'], 8]), ({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 105, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '1015/2', ['1011/2', '1019/2'], 8]), ({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 106, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '509', ['507', '511'], 8]), ({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 107, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '1021/2', ['1017/2', '1025/2'], 8])]
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[True, '503', ['501', '505'], 8][True, '503', ['501', '505'], 8]Passed
fixture 2[False, None, None, 8][False, None, None, 8]Passed
fixture 3[True, '503', ['501', '505'], 8][False, None, None, 8]Failed
fixture 4[False, None, None, 8][False, None, None, 8]Passed
fixture 5[False, None, None, 11][False, None, None, 11]Passed
fixture 6[False, None, None, 0][False, None, None, 0]Passed
fixture 7[True, '515', ['513', '517'], 1][True, '515', ['513', '517'], 1]Passed
fixture 8[False, None, None, 8][False, None, None, 8]Passed
fixture 9[False, None, None, 8][False, None, None, 8]Passed
fixture 10[True, '485', ['483', '487'], 10][True, '485', ['483', '487'], 10]Passed
fixture 11[False, None, None, 8][False, None, None, 8]Passed
fixture 12[True, '503', ['503', '503'], 8][True, '503', ['503', '503'], 8]Passed
variant capture[True, '1009/2', ['1005/2', '1013/2'], 8][True, '1009/2', ['1005/2', '1013/2'], 8]Passed

SHA-256 / 2c34efc94620e5421eb041f3a7b0a59d366e0d6fdc32101f384ec501a0c262e8

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):
    boot_ok = r['boot'] == r['cal_boot']
    generation_ok = True
    age = r['now'] - r['cal_time']
    fresh = 0 <= age < r['ttl']
    delta = r['reading'] - r['source_anchor']
    supported = abs(delta) <= r['radius']
    coordinate = Fraction(delta * r['p'],r['q']) + r['target_anchor']
    low = coordinate - r['error']
    high = coordinate + r['error']
    accepted = boot_ok and generation_ok and fresh and supported and r['error'] >= 0
    return [accepted, str(coordinate) if accepted else None, [str(low),str(high)] if accepted else None,max(0,r['ttl']-age)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [True, '503', ['501', '505'], 8])
check('fixture 2', solve({'boot': 'b', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 3', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 3, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 4', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 1, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 5', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 9, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 11])
check('fixture 6', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 20, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 0])
check('fixture 7', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 19, 'cal_time': 10, 'ttl': 10, 'reading': 110, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [True, '515', ['513', '517'], 1])
check('fixture 8', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 89, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 9', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 111, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [False, None, None, 8])
check('fixture 10', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 10, 'cal_time': 10, 'ttl': 10, 'reading': 90, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}), [True, '485', ['483', '487'], 10])
check('fixture 11', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': -1}), [False, None, None, 8])
check('fixture 12', solve({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 102, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 0}), [True, '503', ['503', '503'], 8])
variant = [({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 103, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '1009/2', ['1005/2', '1013/2'], 8]), ({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 104, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '506', ['504', '508'], 8]), ({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 105, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '1015/2', ['1011/2', '1019/2'], 8]), ({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 106, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '509', ['507', '511'], 8]), ({'boot': 'a', 'cal_boot': 'a', 'generation': 2, 'cal_generation': 2, 'now': 12, 'cal_time': 10, 'ttl': 10, 'reading': 107, 'source_anchor': 100, 'target_anchor': 500, 'p': 3, 'q': 2, 'radius': 10, 'error': 2}, [True, '1021/2', ['1017/2', '1025/2'], 8])]
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[True, '503', ['501', '505'], 8][True, '503', ['501', '505'], 8]Passed
fixture 2[False, None, None, 8][False, None, None, 8]Passed
fixture 3[True, '503', ['501', '505'], 8][False, None, None, 8]Failed
fixture 4[True, '503', ['501', '505'], 8][False, None, None, 8]Failed
fixture 5[False, None, None, 11][False, None, None, 11]Passed
fixture 6[False, None, None, 0][False, None, None, 0]Passed
fixture 7[True, '515', ['513', '517'], 1][True, '515', ['513', '517'], 1]Passed
fixture 8[False, None, None, 8][False, None, None, 8]Passed
fixture 9[False, None, None, 8][False, None, None, 8]Passed
fixture 10[True, '485', ['483', '487'], 10][True, '485', ['483', '487'], 10]Passed
fixture 11[False, None, None, 8][False, None, None, 8]Passed
fixture 12[True, '503', ['503', '503'], 8][True, '503', ['503', '503'], 8]Passed
variant capture[True, '1009/2', ['1005/2', '1013/2'], 8][True, '1009/2', ['1005/2', '1013/2'], 8]Passed

SHA-256 / 86a2c20e006ed314e3da5c9b53772c554b38e78659e662118fb32ce96c139248

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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 2026-09-29T14:39:54.648639+00:00.

Case digest / e25b432455a2ddff66b8686682279e639cb26de694d325f784f67e13ef4f7c4a