FA-636 / Replication / Open access

Admit a conflict resolution result: Replicas execute different resolver versions · case 01

The conflict resolution operation is admitted even though replicas execute different resolver versions.

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

ROOT CAUSE

The admission path omits the resolver version invariant while validating the other operation preconditions.

VERIFIED REPAIR

Require len(set(r['resolver_version'])) == 1 together with every other stated precondition before accepting the operation.

Unsuccessful approach: Adding the resolver version check repairs the reported defect, but replacing the adjacent new dot 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 (set(r['parent_coverage'][0]) <= set(r['parent_coverage'][1])) and (all(a >= b for a,b in zip(r['clock_dominance'][0],r['clock_dominance'][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	`False`	`False`	Passed
Replicas execute different resolver versions	`True`	`False`	Failed
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 / e3ebf3c0aee9d55a8c1dc4e12382caa8aaededc2d85c6f698a73d6b6fb1869e7

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 (all(a >= b for a,b in zip(r['clock_dominance'][0],r['clock_dominance'][1]))) and (len(set(r['resolver_version'])) == 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	`False`	`False`	Passed
Replicas execute different resolver versions	`False`	`False`	Passed
Resolution reuses an existing causal operation dot	`True`	`False`	Failed
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 / faf42feaa97be464b98dc78a6d6d4536f44e04d01f8f179ca3d424f9e7cad7fd

3 / The verified repair

Exit 0

"""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 (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	`False`	`False`	Passed
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 / fd9bde29ab767e645725d066a6025b043cf80350f0ad83f5559ff1b1b200a994

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 2026-09-29T14:36:54.850098+00:00.

Case digest / 6fc521d383cc9807f282ad758a40be20a0c11e5a576f5a0028bc9bdf5dad3f92