FA-626 / Replication / Open access

Admit a conflict resolution result: The resolution omits a known conflicting parent · case 01

The conflict resolution operation is admitted even though the resolution omits a known conflicting parent.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The admission path omits the parent coverage invariant while validating the other operation preconditions.

THE FAILURE

The admission path omits the parent coverage invariant while validating the other operation preconditions.

Unsuccessful approach: Adding the parent coverage check repairs the reported defect, but replacing the adjacent clock dominance check loses that independent invariant.

Case contract

Return a Boolean admission decision for admit a conflict resolution result. The record r must satisfy all of: set(r['parent_coverage'][0]) <= set(r['parent_coverage'][1]); all(a >= b for a,b in zip(r['clock_dominance'][0],r['clock_dominance'][1])); len(set(r['resolver_version'])) == 1; tuple(r['new_dot'][0]) not in [tuple(x) for x in r['new_dot'][1]]; r['result_domain'] >= 0. Extra tracing fields are ignored; validation does not mutate the record.

Why this case matters

A deterministic local contract for replication. Each negative fixture violates exactly one invariant. No transport timing, persistence, cryptographic verification, or full protocol implementation is claimed.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(r):
    return (all(a >= b for a,b in zip(r['clock_dominance'][0],r['clock_dominance'][1]))) and (len(set(r['resolver_version'])) == 1) and (tuple(r['new_dot'][0]) not in [tuple(x) for x in r['new_dot'][1]]) and (r['result_domain'] >= 0)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
r = {'parent_coverage': [['a', 'b'], ['a', 'b', 'c']], 'clock_dominance': [[3, 4], [2, 4]], 'resolver_version': [3, 3, 3], 'new_dot': [['a', 4], [['a', 3]]], 'result_domain': 0}
check('valid operation', solve(r), True)
check('The resolution omits a known conflicting parent', solve(dict(r, **{'parent_coverage': [['a', 'b'], ['a']]})), False)
check('The resolved clock regresses a parent component', solve(dict(r, **{'clock_dominance': [[3, 3], [2, 4]]})), False)
check('Replicas execute different resolver versions', solve(dict(r, **{'resolver_version': [3, 2, 3]})), False)
check('Resolution reuses an existing causal operation dot', solve(dict(r, **{'new_dot': [['a', 3], [['a', 3]]]})), False)
check('A merge result violates the application value constraint', solve(dict(r, **{'result_domain': -1})), False)
check('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)
check('repeat validation is pure', solve(r), True)
invalid = {'parent_coverage': [['a', 'b'], ['a']], 'clock_dominance': [[3, 3], [2, 4]], 'resolver_version': [3, 2, 3], 'new_dot': [['a', 3], [['a', 3]]], 'result_domain': -1}
keys = list(invalid)
pair = {keys[N % len(keys)]: invalid[keys[N % len(keys)]], keys[(N+1) % len(keys)]: invalid[keys[(N+1) % len(keys)]]}
check('two independent violations in variant', solve(dict(r, **pair)), False)
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 fixture	Actual	Expected	Outcome
valid operation	`True`	`True`	Passed
The resolution omits a known conflicting parent	`True`	`False`	Failed
The resolved clock regresses a parent component	`False`	`False`	Passed
Replicas execute different resolver versions	`False`	`False`	Passed
Resolution reuses an existing causal operation dot	`False`	`False`	Passed
A merge result violates the application value constraint	`False`	`False`	Passed
unrelated tracing metadata	`True`	`True`	Passed
repeat validation is pure	`True`	`True`	Passed
two independent violations in variant	`False`	`False`	Passed

SHA-256 / b24144c59d5e215e85377f7f5996003a6150df37fc5aa00ea7957e658580e153

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(r):
    return (set(r['parent_coverage'][0]) <= set(r['parent_coverage'][1])) and (len(set(r['resolver_version'])) == 1) and (tuple(r['new_dot'][0]) not in [tuple(x) for x in r['new_dot'][1]]) and (r['result_domain'] >= 0)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
r = {'parent_coverage': [['a', 'b'], ['a', 'b', 'c']], 'clock_dominance': [[3, 4], [2, 4]], 'resolver_version': [3, 3, 3], 'new_dot': [['a', 4], [['a', 3]]], 'result_domain': 0}
check('valid operation', solve(r), True)
check('The resolution omits a known conflicting parent', solve(dict(r, **{'parent_coverage': [['a', 'b'], ['a']]})), False)
check('The resolved clock regresses a parent component', solve(dict(r, **{'clock_dominance': [[3, 3], [2, 4]]})), False)
check('Replicas execute different resolver versions', solve(dict(r, **{'resolver_version': [3, 2, 3]})), False)
check('Resolution reuses an existing causal operation dot', solve(dict(r, **{'new_dot': [['a', 3], [['a', 3]]]})), False)
check('A merge result violates the application value constraint', solve(dict(r, **{'result_domain': -1})), False)
check('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)
check('repeat validation is pure', solve(r), True)
invalid = {'parent_coverage': [['a', 'b'], ['a']], 'clock_dominance': [[3, 3], [2, 4]], 'resolver_version': [3, 2, 3], 'new_dot': [['a', 3], [['a', 3]]], 'result_domain': -1}
keys = list(invalid)
pair = {keys[N % len(keys)]: invalid[keys[N % len(keys)]], keys[(N+1) % len(keys)]: invalid[keys[(N+1) % len(keys)]]}
check('two independent violations in variant', solve(dict(r, **pair)), False)
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 fixture	Actual	Expected	Outcome
valid operation	`True`	`True`	Passed
The resolution omits a known conflicting parent	`False`	`False`	Passed
The resolved clock regresses a parent component	`True`	`False`	Failed
Replicas execute different resolver versions	`False`	`False`	Passed
Resolution reuses an existing causal operation dot	`False`	`False`	Passed
A merge result violates the application value constraint	`False`	`False`	Passed
unrelated tracing metadata	`True`	`True`	Passed
repeat validation is pure	`True`	`True`	Passed
two independent violations in variant	`False`	`False`	Passed

SHA-256 / 6e387274c00a2663b18ba7184703928b427448c441ff40ebecccf089e48bd72a

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 9 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.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

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 2026-09-29T14:36:54.848592+00:00.

Case digest / 4d1279dbca79b0b2bcf81daed09979650e34416f6523b9ce0aa1703b5f1e11e7