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FA-35296 / Notification interfaces / Open access

Notification handoff to another surface: remote-accepted from handoff-pending · case 01

The remote-accepted event leaves a notification in remote-visible instead of remote-mounting.

Verified by executionVariant 1 · 36 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Remote receipt is confused with successful remote display.

VERIFIED REPAIR

Commit the handoff-pending / remote-accepted transition to remote-mounting; preserve the other explicitly stipulated transitions.

Unsuccessful approach: Dropping local visibility on receipt loses fallback during mount failure.

Case contract

Notification handoff to another surface is a bounded visual-notification workflow with mutable policy state {'transfer': 4, 'local': True, 'remote': False, 'remote_owner': 'tablet'}. Its default transition relation is {('local-visible', 'send-to-other-surface'): 'handoff-pending', ('handoff-pending', 'remote-accepted'): 'remote-mounting', ('remote-mounting', 'remote-painted'): 'remote-visible', ('remote-mounting', 'remote-paint-failed'): 'handoff-error', ('handoff-pending', 'remote-rejected'): 'handoff-error', ('handoff-error', 'retry-handoff'): 'handoff-pending', ('remote-visible', 'bring-back'): 'recall-pending', ('recall-pending', 'remote-released'): 'local-remounting', ('local-remounting', 'local-painted'): 'local-visible', ('handoff-pending', 'cancel-handoff'): 'cancel-pending'}; domain inputs can suppress or redirect transitions and update policy fields, as specified in solve. Different-generation events are inert. Batches apply in order. Optional observe returns the selected policy field alongside the phase.

Why this case matters

Visual notification lifecycle ordering can leave an inbox or toast showing the wrong actionable state even when transport succeeds.

1 / The failure

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

N = 1
observations = []
def solve(initial, events, generation, payload=None, observe=None):
    table = {('local-visible', 'send-to-other-surface'): 'handoff-pending', ('handoff-pending', 'remote-accepted'): 'remote-visible', ('remote-mounting', 'remote-painted'): 'remote-visible', ('remote-mounting', 'remote-paint-failed'): 'handoff-error', ('handoff-pending', 'remote-rejected'): 'handoff-error', ('handoff-error', 'retry-handoff'): 'handoff-pending', ('remote-visible', 'bring-back'): 'recall-pending', ('recall-pending', 'remote-released'): 'local-remounting', ('local-remounting', 'local-painted'): 'local-visible', ('handoff-pending', 'cancel-handoff'): 'cancel-pending'}
    data = json.loads(json.dumps({'transfer': 4, 'local': True, 'remote': False, 'remote_owner': 'tablet'})) if payload is None else {**json.loads(json.dumps({'transfer': 4, 'local': True, 'remote': False, 'remote_owner': 'tablet'})), **json.loads(json.dumps(payload))}
    state = initial
    for delivery in events:
        event, event_generation = delivery[:2]
        arg = delivery[2] if len(delivery) > 2 else {}
        if event_generation == generation:
            previous = state
            if event in ('remote-accepted','remote-painted','remote-released','remote-rejected','remote-paint-failed'):
                if arg.get('transfer',data['transfer']) != data['transfer'] or arg.get('owner',data['remote_owner']) != data['remote_owner']: event = 'unknown-event'
            if event == 'remote-painted': data['remote'] = True
            if event == 'remote-released': data['remote'] = False
            state = table.get((state, event), state)
            if state == 'remote-visible': data['local'] = False
            if state in ('local-visible','handoff-error'): data['local'] = True
            if state == 'local-hidden': data['local'] = False
    return {'phase': state, 'value': data[observe]} if observe else state
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('local-visible / send-to-other-surface', solve('local-visible', [('send-to-other-surface', N)], N), 'handoff-pending')
check('handoff-pending / remote-accepted', solve('handoff-pending', [('remote-accepted', N)], N), 'remote-mounting')
check('remote-mounting / remote-painted', solve('remote-mounting', [('remote-painted', N)], N), 'remote-visible')
check('remote-mounting / remote-paint-failed', solve('remote-mounting', [('remote-paint-failed', N)], N), 'handoff-error')
check('handoff-pending / remote-rejected', solve('handoff-pending', [('remote-rejected', N)], N), 'handoff-error')
check('handoff-error / retry-handoff', solve('handoff-error', [('retry-handoff', N)], N), 'handoff-pending')
check('remote-visible / bring-back', solve('remote-visible', [('bring-back', N)], N), 'recall-pending')
check('recall-pending / remote-released', solve('recall-pending', [('remote-released', N)], N), 'local-remounting')
check('local-remounting / local-painted', solve('local-remounting', [('local-painted', N)], N), 'local-visible')
check('handoff-pending / cancel-handoff', solve('handoff-pending', [('cancel-handoff', N)], N), 'cancel-pending')
check('older notification incarnation', solve('local-visible', [('send-to-other-surface', N - 1)], N), 'local-visible')
check('future notification incarnation', solve('local-visible', [('send-to-other-surface', N + 1)], N), 'local-visible')
check('unknown event is inert', solve('local-visible', [('unknown-event', N)], N), 'local-visible')
check('empty delivery batch', solve('local-visible', [], N), 'local-visible')
check('N stale deliveries before current delivery', solve('local-visible', [('send-to-other-surface', N - 1)] * N + [('send-to-other-surface', N)], N), 'handoff-pending')
check('trace send-to-other-surface then remote-accepted', solve('local-visible', [('send-to-other-surface', N), ('remote-accepted', N)], N), 'remote-mounting')
check('trace send-to-other-surface then remote-rejected', solve('local-visible', [('send-to-other-surface', N), ('remote-rejected', N)], N), 'handoff-error')
check('trace send-to-other-surface then cancel-handoff', solve('local-visible', [('send-to-other-surface', N), ('cancel-handoff', N)], N), 'cancel-pending')
check('trace remote-accepted then remote-painted', solve('handoff-pending', [('remote-accepted', N), ('remote-painted', N)], N), 'remote-visible')
check('trace remote-accepted then remote-paint-failed', solve('handoff-pending', [('remote-accepted', N), ('remote-paint-failed', N)], N), 'handoff-error')
check('trace remote-painted then bring-back', solve('remote-mounting', [('remote-painted', N), ('bring-back', N)], N), 'recall-pending')
check('trace remote-paint-failed then retry-handoff', solve('remote-mounting', [('remote-paint-failed', N), ('retry-handoff', N)], N), 'handoff-pending')
check('trace remote-rejected then retry-handoff', solve('handoff-pending', [('remote-rejected', N), ('retry-handoff', N)], N), 'handoff-pending')
check('trace retry-handoff then remote-accepted', solve('handoff-error', [('retry-handoff', N), ('remote-accepted', N)], N), 'remote-mounting')
check('trace retry-handoff then remote-rejected', solve('handoff-error', [('retry-handoff', N), ('remote-rejected', N)], N), 'handoff-error')
check('trace retry-handoff then cancel-handoff', solve('handoff-error', [('retry-handoff', N), ('cancel-handoff', N)], N), 'cancel-pending')
check('trace bring-back then remote-released', solve('remote-visible', [('bring-back', N), ('remote-released', N)], N), 'local-remounting')
check('trace remote-released then local-painted', solve('recall-pending', [('remote-released', N), ('local-painted', N)], N), 'local-visible')
check('trace local-painted then send-to-other-surface', solve('local-remounting', [('local-painted', N), ('send-to-other-surface', N)], N), 'handoff-pending')
check('domain state regression 1: local', solve('handoff-pending', [('remote-accepted', N, {'transfer': 3})], N, {}, 'local'), {'phase': 'handoff-pending', 'value': True})
check('domain state regression 2: remote', solve('remote-mounting', [('remote-painted', N, {'owner': 'phone'})], N, {}, 'remote'), {'phase': 'remote-mounting', 'value': False})
check('domain state regression 3: local', solve('remote-mounting', [('remote-painted', N, {})], N, {}, 'local'), {'phase': 'remote-visible', 'value': False})
check('domain state regression 4: local', solve('remote-mounting', [('remote-paint-failed', N, {})], N, {}, 'local'), {'phase': 'handoff-error', 'value': True})
check('domain state regression 5: remote', solve('recall-pending', [('remote-released', N, {})], N, {'local': False, 'remote': True}, 'remote'), {'phase': 'local-remounting', 'value': False})
check('domain state regression 6: local', solve('local-remounting', [('local-painted', N, {})], N, {'local': False, 'remote': False}, 'local'), {'phase': 'local-visible', 'value': True})
check('domain state regression 7: remote', solve('local-visible', [('send-to-other-surface', N, {}), ('remote-accepted', N, {}), ('remote-painted', N, {}), ('bring-back', N, {}), ('remote-released', N, {}), ('local-painted', N, {})], N, {}, 'remote'), {'phase': 'local-visible', 'value': 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 fixtureActualExpectedOutcome
local-visible / send-to-other-surfacehandoff-pendinghandoff-pendingPassed
handoff-pending / remote-acceptedremote-visibleremote-mountingFailed
remote-mounting / remote-paintedremote-visibleremote-visiblePassed
remote-mounting / remote-paint-failedhandoff-errorhandoff-errorPassed
handoff-pending / remote-rejectedhandoff-errorhandoff-errorPassed
handoff-error / retry-handoffhandoff-pendinghandoff-pendingPassed
remote-visible / bring-backrecall-pendingrecall-pendingPassed
recall-pending / remote-releasedlocal-remountinglocal-remountingPassed
local-remounting / local-paintedlocal-visiblelocal-visiblePassed
handoff-pending / cancel-handoffcancel-pendingcancel-pendingPassed
older notification incarnationlocal-visiblelocal-visiblePassed
future notification incarnationlocal-visiblelocal-visiblePassed
unknown event is inertlocal-visiblelocal-visiblePassed
empty delivery batchlocal-visiblelocal-visiblePassed
N stale deliveries before current deliveryhandoff-pendinghandoff-pendingPassed
trace send-to-other-surface then remote-acceptedremote-visibleremote-mountingFailed
trace send-to-other-surface then remote-rejectedhandoff-errorhandoff-errorPassed
trace send-to-other-surface then cancel-handoffcancel-pendingcancel-pendingPassed
trace remote-accepted then remote-paintedremote-visibleremote-visiblePassed
trace remote-accepted then remote-paint-failedremote-visiblehandoff-errorFailed
trace remote-painted then bring-backrecall-pendingrecall-pendingPassed
trace remote-paint-failed then retry-handoffhandoff-pendinghandoff-pendingPassed
trace remote-rejected then retry-handoffhandoff-pendinghandoff-pendingPassed
trace retry-handoff then remote-acceptedremote-visibleremote-mountingFailed
trace retry-handoff then remote-rejectedhandoff-errorhandoff-errorPassed
trace retry-handoff then cancel-handoffcancel-pendingcancel-pendingPassed
trace bring-back then remote-releasedlocal-remountinglocal-remountingPassed
trace remote-released then local-paintedlocal-visiblelocal-visiblePassed
trace local-painted then send-to-other-surfacehandoff-pendinghandoff-pendingPassed
domain state regression 1: local{'phase': 'handoff-pending', 'value': True}{'phase': 'handoff-pending', 'value': True}Passed
domain state regression 2: remote{'phase': 'remote-mounting', 'value': False}{'phase': 'remote-mounting', 'value': False}Passed
domain state regression 3: local{'phase': 'remote-visible', 'value': False}{'phase': 'remote-visible', 'value': False}Passed
domain state regression 4: local{'phase': 'handoff-error', 'value': True}{'phase': 'handoff-error', 'value': True}Passed
domain state regression 5: remote{'phase': 'local-remounting', 'value': False}{'phase': 'local-remounting', 'value': False}Passed
domain state regression 6: local{'phase': 'local-visible', 'value': True}{'phase': 'local-visible', 'value': True}Passed
domain state regression 7: remote{'phase': 'local-visible', 'value': False}{'phase': 'local-visible', 'value': False}Passed

SHA-256 / 56f87130bae8b8133fb027c52afd2d667c045fcb128591eee0027e45bfcb7573

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(initial, events, generation, payload=None, observe=None):
    table = {('local-visible', 'send-to-other-surface'): 'handoff-pending', ('handoff-pending', 'remote-accepted'): 'local-hidden', ('remote-mounting', 'remote-painted'): 'remote-visible', ('remote-mounting', 'remote-paint-failed'): 'handoff-error', ('handoff-pending', 'remote-rejected'): 'handoff-error', ('handoff-error', 'retry-handoff'): 'handoff-pending', ('remote-visible', 'bring-back'): 'recall-pending', ('recall-pending', 'remote-released'): 'local-remounting', ('local-remounting', 'local-painted'): 'local-visible', ('handoff-pending', 'cancel-handoff'): 'cancel-pending'}
    data = json.loads(json.dumps({'transfer': 4, 'local': True, 'remote': False, 'remote_owner': 'tablet'})) if payload is None else {**json.loads(json.dumps({'transfer': 4, 'local': True, 'remote': False, 'remote_owner': 'tablet'})), **json.loads(json.dumps(payload))}
    state = initial
    for delivery in events:
        event, event_generation = delivery[:2]
        arg = delivery[2] if len(delivery) > 2 else {}
        if event_generation == generation:
            previous = state
            if event in ('remote-accepted','remote-painted','remote-released','remote-rejected','remote-paint-failed'):
                if arg.get('transfer',data['transfer']) != data['transfer'] or arg.get('owner',data['remote_owner']) != data['remote_owner']: event = 'unknown-event'
            if event == 'remote-painted': data['remote'] = True
            if event == 'remote-released': data['remote'] = False
            state = table.get((state, event), state)
            if state == 'remote-visible': data['local'] = False
            if state in ('local-visible','handoff-error'): data['local'] = True
            if state == 'local-hidden': data['local'] = False
    return {'phase': state, 'value': data[observe]} if observe else state
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('local-visible / send-to-other-surface', solve('local-visible', [('send-to-other-surface', N)], N), 'handoff-pending')
check('handoff-pending / remote-accepted', solve('handoff-pending', [('remote-accepted', N)], N), 'remote-mounting')
check('remote-mounting / remote-painted', solve('remote-mounting', [('remote-painted', N)], N), 'remote-visible')
check('remote-mounting / remote-paint-failed', solve('remote-mounting', [('remote-paint-failed', N)], N), 'handoff-error')
check('handoff-pending / remote-rejected', solve('handoff-pending', [('remote-rejected', N)], N), 'handoff-error')
check('handoff-error / retry-handoff', solve('handoff-error', [('retry-handoff', N)], N), 'handoff-pending')
check('remote-visible / bring-back', solve('remote-visible', [('bring-back', N)], N), 'recall-pending')
check('recall-pending / remote-released', solve('recall-pending', [('remote-released', N)], N), 'local-remounting')
check('local-remounting / local-painted', solve('local-remounting', [('local-painted', N)], N), 'local-visible')
check('handoff-pending / cancel-handoff', solve('handoff-pending', [('cancel-handoff', N)], N), 'cancel-pending')
check('older notification incarnation', solve('local-visible', [('send-to-other-surface', N - 1)], N), 'local-visible')
check('future notification incarnation', solve('local-visible', [('send-to-other-surface', N + 1)], N), 'local-visible')
check('unknown event is inert', solve('local-visible', [('unknown-event', N)], N), 'local-visible')
check('empty delivery batch', solve('local-visible', [], N), 'local-visible')
check('N stale deliveries before current delivery', solve('local-visible', [('send-to-other-surface', N - 1)] * N + [('send-to-other-surface', N)], N), 'handoff-pending')
check('trace send-to-other-surface then remote-accepted', solve('local-visible', [('send-to-other-surface', N), ('remote-accepted', N)], N), 'remote-mounting')
check('trace send-to-other-surface then remote-rejected', solve('local-visible', [('send-to-other-surface', N), ('remote-rejected', N)], N), 'handoff-error')
check('trace send-to-other-surface then cancel-handoff', solve('local-visible', [('send-to-other-surface', N), ('cancel-handoff', N)], N), 'cancel-pending')
check('trace remote-accepted then remote-painted', solve('handoff-pending', [('remote-accepted', N), ('remote-painted', N)], N), 'remote-visible')
check('trace remote-accepted then remote-paint-failed', solve('handoff-pending', [('remote-accepted', N), ('remote-paint-failed', N)], N), 'handoff-error')
check('trace remote-painted then bring-back', solve('remote-mounting', [('remote-painted', N), ('bring-back', N)], N), 'recall-pending')
check('trace remote-paint-failed then retry-handoff', solve('remote-mounting', [('remote-paint-failed', N), ('retry-handoff', N)], N), 'handoff-pending')
check('trace remote-rejected then retry-handoff', solve('handoff-pending', [('remote-rejected', N), ('retry-handoff', N)], N), 'handoff-pending')
check('trace retry-handoff then remote-accepted', solve('handoff-error', [('retry-handoff', N), ('remote-accepted', N)], N), 'remote-mounting')
check('trace retry-handoff then remote-rejected', solve('handoff-error', [('retry-handoff', N), ('remote-rejected', N)], N), 'handoff-error')
check('trace retry-handoff then cancel-handoff', solve('handoff-error', [('retry-handoff', N), ('cancel-handoff', N)], N), 'cancel-pending')
check('trace bring-back then remote-released', solve('remote-visible', [('bring-back', N), ('remote-released', N)], N), 'local-remounting')
check('trace remote-released then local-painted', solve('recall-pending', [('remote-released', N), ('local-painted', N)], N), 'local-visible')
check('trace local-painted then send-to-other-surface', solve('local-remounting', [('local-painted', N), ('send-to-other-surface', N)], N), 'handoff-pending')
check('domain state regression 1: local', solve('handoff-pending', [('remote-accepted', N, {'transfer': 3})], N, {}, 'local'), {'phase': 'handoff-pending', 'value': True})
check('domain state regression 2: remote', solve('remote-mounting', [('remote-painted', N, {'owner': 'phone'})], N, {}, 'remote'), {'phase': 'remote-mounting', 'value': False})
check('domain state regression 3: local', solve('remote-mounting', [('remote-painted', N, {})], N, {}, 'local'), {'phase': 'remote-visible', 'value': False})
check('domain state regression 4: local', solve('remote-mounting', [('remote-paint-failed', N, {})], N, {}, 'local'), {'phase': 'handoff-error', 'value': True})
check('domain state regression 5: remote', solve('recall-pending', [('remote-released', N, {})], N, {'local': False, 'remote': True}, 'remote'), {'phase': 'local-remounting', 'value': False})
check('domain state regression 6: local', solve('local-remounting', [('local-painted', N, {})], N, {'local': False, 'remote': False}, 'local'), {'phase': 'local-visible', 'value': True})
check('domain state regression 7: remote', solve('local-visible', [('send-to-other-surface', N, {}), ('remote-accepted', N, {}), ('remote-painted', N, {}), ('bring-back', N, {}), ('remote-released', N, {}), ('local-painted', N, {})], N, {}, 'remote'), {'phase': 'local-visible', 'value': 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 fixtureActualExpectedOutcome
local-visible / send-to-other-surfacehandoff-pendinghandoff-pendingPassed
handoff-pending / remote-acceptedlocal-hiddenremote-mountingFailed
remote-mounting / remote-paintedremote-visibleremote-visiblePassed
remote-mounting / remote-paint-failedhandoff-errorhandoff-errorPassed
handoff-pending / remote-rejectedhandoff-errorhandoff-errorPassed
handoff-error / retry-handoffhandoff-pendinghandoff-pendingPassed
remote-visible / bring-backrecall-pendingrecall-pendingPassed
recall-pending / remote-releasedlocal-remountinglocal-remountingPassed
local-remounting / local-paintedlocal-visiblelocal-visiblePassed
handoff-pending / cancel-handoffcancel-pendingcancel-pendingPassed
older notification incarnationlocal-visiblelocal-visiblePassed
future notification incarnationlocal-visiblelocal-visiblePassed
unknown event is inertlocal-visiblelocal-visiblePassed
empty delivery batchlocal-visiblelocal-visiblePassed
N stale deliveries before current deliveryhandoff-pendinghandoff-pendingPassed
trace send-to-other-surface then remote-acceptedlocal-hiddenremote-mountingFailed
trace send-to-other-surface then remote-rejectedhandoff-errorhandoff-errorPassed
trace send-to-other-surface then cancel-handoffcancel-pendingcancel-pendingPassed
trace remote-accepted then remote-paintedlocal-hiddenremote-visibleFailed
trace remote-accepted then remote-paint-failedlocal-hiddenhandoff-errorFailed
trace remote-painted then bring-backrecall-pendingrecall-pendingPassed
trace remote-paint-failed then retry-handoffhandoff-pendinghandoff-pendingPassed
trace remote-rejected then retry-handoffhandoff-pendinghandoff-pendingPassed
trace retry-handoff then remote-acceptedlocal-hiddenremote-mountingFailed
trace retry-handoff then remote-rejectedhandoff-errorhandoff-errorPassed
trace retry-handoff then cancel-handoffcancel-pendingcancel-pendingPassed
trace bring-back then remote-releasedlocal-remountinglocal-remountingPassed
trace remote-released then local-paintedlocal-visiblelocal-visiblePassed
trace local-painted then send-to-other-surfacehandoff-pendinghandoff-pendingPassed
domain state regression 1: local{'phase': 'handoff-pending', 'value': True}{'phase': 'handoff-pending', 'value': True}Passed
domain state regression 2: remote{'phase': 'remote-mounting', 'value': False}{'phase': 'remote-mounting', 'value': False}Passed
domain state regression 3: local{'phase': 'remote-visible', 'value': False}{'phase': 'remote-visible', 'value': False}Passed
domain state regression 4: local{'phase': 'handoff-error', 'value': True}{'phase': 'handoff-error', 'value': True}Passed
domain state regression 5: remote{'phase': 'local-remounting', 'value': False}{'phase': 'local-remounting', 'value': False}Passed
domain state regression 6: local{'phase': 'local-visible', 'value': True}{'phase': 'local-visible', 'value': True}Passed
domain state regression 7: remote{'phase': 'local-hidden', 'value': False}{'phase': 'local-visible', 'value': False}Failed

SHA-256 / 2d474c6cf9132ff5d2b76e099eec5e37eb8f59af47dab9aca7e445939861c596

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(initial, events, generation, payload=None, observe=None):
    table = {('local-visible', 'send-to-other-surface'): 'handoff-pending', ('handoff-pending', 'remote-accepted'): 'remote-mounting', ('remote-mounting', 'remote-painted'): 'remote-visible', ('remote-mounting', 'remote-paint-failed'): 'handoff-error', ('handoff-pending', 'remote-rejected'): 'handoff-error', ('handoff-error', 'retry-handoff'): 'handoff-pending', ('remote-visible', 'bring-back'): 'recall-pending', ('recall-pending', 'remote-released'): 'local-remounting', ('local-remounting', 'local-painted'): 'local-visible', ('handoff-pending', 'cancel-handoff'): 'cancel-pending'}
    data = json.loads(json.dumps({'transfer': 4, 'local': True, 'remote': False, 'remote_owner': 'tablet'})) if payload is None else {**json.loads(json.dumps({'transfer': 4, 'local': True, 'remote': False, 'remote_owner': 'tablet'})), **json.loads(json.dumps(payload))}
    state = initial
    for delivery in events:
        event, event_generation = delivery[:2]
        arg = delivery[2] if len(delivery) > 2 else {}
        if event_generation == generation:
            previous = state
            if event in ('remote-accepted','remote-painted','remote-released','remote-rejected','remote-paint-failed'):
                if arg.get('transfer',data['transfer']) != data['transfer'] or arg.get('owner',data['remote_owner']) != data['remote_owner']: event = 'unknown-event'
            if event == 'remote-painted': data['remote'] = True
            if event == 'remote-released': data['remote'] = False
            state = table.get((state, event), state)
            if state == 'remote-visible': data['local'] = False
            if state in ('local-visible','handoff-error'): data['local'] = True
            if state == 'local-hidden': data['local'] = False
    return {'phase': state, 'value': data[observe]} if observe else state
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('local-visible / send-to-other-surface', solve('local-visible', [('send-to-other-surface', N)], N), 'handoff-pending')
check('handoff-pending / remote-accepted', solve('handoff-pending', [('remote-accepted', N)], N), 'remote-mounting')
check('remote-mounting / remote-painted', solve('remote-mounting', [('remote-painted', N)], N), 'remote-visible')
check('remote-mounting / remote-paint-failed', solve('remote-mounting', [('remote-paint-failed', N)], N), 'handoff-error')
check('handoff-pending / remote-rejected', solve('handoff-pending', [('remote-rejected', N)], N), 'handoff-error')
check('handoff-error / retry-handoff', solve('handoff-error', [('retry-handoff', N)], N), 'handoff-pending')
check('remote-visible / bring-back', solve('remote-visible', [('bring-back', N)], N), 'recall-pending')
check('recall-pending / remote-released', solve('recall-pending', [('remote-released', N)], N), 'local-remounting')
check('local-remounting / local-painted', solve('local-remounting', [('local-painted', N)], N), 'local-visible')
check('handoff-pending / cancel-handoff', solve('handoff-pending', [('cancel-handoff', N)], N), 'cancel-pending')
check('older notification incarnation', solve('local-visible', [('send-to-other-surface', N - 1)], N), 'local-visible')
check('future notification incarnation', solve('local-visible', [('send-to-other-surface', N + 1)], N), 'local-visible')
check('unknown event is inert', solve('local-visible', [('unknown-event', N)], N), 'local-visible')
check('empty delivery batch', solve('local-visible', [], N), 'local-visible')
check('N stale deliveries before current delivery', solve('local-visible', [('send-to-other-surface', N - 1)] * N + [('send-to-other-surface', N)], N), 'handoff-pending')
check('trace send-to-other-surface then remote-accepted', solve('local-visible', [('send-to-other-surface', N), ('remote-accepted', N)], N), 'remote-mounting')
check('trace send-to-other-surface then remote-rejected', solve('local-visible', [('send-to-other-surface', N), ('remote-rejected', N)], N), 'handoff-error')
check('trace send-to-other-surface then cancel-handoff', solve('local-visible', [('send-to-other-surface', N), ('cancel-handoff', N)], N), 'cancel-pending')
check('trace remote-accepted then remote-painted', solve('handoff-pending', [('remote-accepted', N), ('remote-painted', N)], N), 'remote-visible')
check('trace remote-accepted then remote-paint-failed', solve('handoff-pending', [('remote-accepted', N), ('remote-paint-failed', N)], N), 'handoff-error')
check('trace remote-painted then bring-back', solve('remote-mounting', [('remote-painted', N), ('bring-back', N)], N), 'recall-pending')
check('trace remote-paint-failed then retry-handoff', solve('remote-mounting', [('remote-paint-failed', N), ('retry-handoff', N)], N), 'handoff-pending')
check('trace remote-rejected then retry-handoff', solve('handoff-pending', [('remote-rejected', N), ('retry-handoff', N)], N), 'handoff-pending')
check('trace retry-handoff then remote-accepted', solve('handoff-error', [('retry-handoff', N), ('remote-accepted', N)], N), 'remote-mounting')
check('trace retry-handoff then remote-rejected', solve('handoff-error', [('retry-handoff', N), ('remote-rejected', N)], N), 'handoff-error')
check('trace retry-handoff then cancel-handoff', solve('handoff-error', [('retry-handoff', N), ('cancel-handoff', N)], N), 'cancel-pending')
check('trace bring-back then remote-released', solve('remote-visible', [('bring-back', N), ('remote-released', N)], N), 'local-remounting')
check('trace remote-released then local-painted', solve('recall-pending', [('remote-released', N), ('local-painted', N)], N), 'local-visible')
check('trace local-painted then send-to-other-surface', solve('local-remounting', [('local-painted', N), ('send-to-other-surface', N)], N), 'handoff-pending')
check('domain state regression 1: local', solve('handoff-pending', [('remote-accepted', N, {'transfer': 3})], N, {}, 'local'), {'phase': 'handoff-pending', 'value': True})
check('domain state regression 2: remote', solve('remote-mounting', [('remote-painted', N, {'owner': 'phone'})], N, {}, 'remote'), {'phase': 'remote-mounting', 'value': False})
check('domain state regression 3: local', solve('remote-mounting', [('remote-painted', N, {})], N, {}, 'local'), {'phase': 'remote-visible', 'value': False})
check('domain state regression 4: local', solve('remote-mounting', [('remote-paint-failed', N, {})], N, {}, 'local'), {'phase': 'handoff-error', 'value': True})
check('domain state regression 5: remote', solve('recall-pending', [('remote-released', N, {})], N, {'local': False, 'remote': True}, 'remote'), {'phase': 'local-remounting', 'value': False})
check('domain state regression 6: local', solve('local-remounting', [('local-painted', N, {})], N, {'local': False, 'remote': False}, 'local'), {'phase': 'local-visible', 'value': True})
check('domain state regression 7: remote', solve('local-visible', [('send-to-other-surface', N, {}), ('remote-accepted', N, {}), ('remote-painted', N, {}), ('bring-back', N, {}), ('remote-released', N, {}), ('local-painted', N, {})], N, {}, 'remote'), {'phase': 'local-visible', 'value': 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 fixtureActualExpectedOutcome
local-visible / send-to-other-surfacehandoff-pendinghandoff-pendingPassed
handoff-pending / remote-acceptedremote-mountingremote-mountingPassed
remote-mounting / remote-paintedremote-visibleremote-visiblePassed
remote-mounting / remote-paint-failedhandoff-errorhandoff-errorPassed
handoff-pending / remote-rejectedhandoff-errorhandoff-errorPassed
handoff-error / retry-handoffhandoff-pendinghandoff-pendingPassed
remote-visible / bring-backrecall-pendingrecall-pendingPassed
recall-pending / remote-releasedlocal-remountinglocal-remountingPassed
local-remounting / local-paintedlocal-visiblelocal-visiblePassed
handoff-pending / cancel-handoffcancel-pendingcancel-pendingPassed
older notification incarnationlocal-visiblelocal-visiblePassed
future notification incarnationlocal-visiblelocal-visiblePassed
unknown event is inertlocal-visiblelocal-visiblePassed
empty delivery batchlocal-visiblelocal-visiblePassed
N stale deliveries before current deliveryhandoff-pendinghandoff-pendingPassed
trace send-to-other-surface then remote-acceptedremote-mountingremote-mountingPassed
trace send-to-other-surface then remote-rejectedhandoff-errorhandoff-errorPassed
trace send-to-other-surface then cancel-handoffcancel-pendingcancel-pendingPassed
trace remote-accepted then remote-paintedremote-visibleremote-visiblePassed
trace remote-accepted then remote-paint-failedhandoff-errorhandoff-errorPassed
trace remote-painted then bring-backrecall-pendingrecall-pendingPassed
trace remote-paint-failed then retry-handoffhandoff-pendinghandoff-pendingPassed
trace remote-rejected then retry-handoffhandoff-pendinghandoff-pendingPassed
trace retry-handoff then remote-acceptedremote-mountingremote-mountingPassed
trace retry-handoff then remote-rejectedhandoff-errorhandoff-errorPassed
trace retry-handoff then cancel-handoffcancel-pendingcancel-pendingPassed
trace bring-back then remote-releasedlocal-remountinglocal-remountingPassed
trace remote-released then local-paintedlocal-visiblelocal-visiblePassed
trace local-painted then send-to-other-surfacehandoff-pendinghandoff-pendingPassed
domain state regression 1: local{'phase': 'handoff-pending', 'value': True}{'phase': 'handoff-pending', 'value': True}Passed
domain state regression 2: remote{'phase': 'remote-mounting', 'value': False}{'phase': 'remote-mounting', 'value': False}Passed
domain state regression 3: local{'phase': 'remote-visible', 'value': False}{'phase': 'remote-visible', 'value': False}Passed
domain state regression 4: local{'phase': 'handoff-error', 'value': True}{'phase': 'handoff-error', 'value': True}Passed
domain state regression 5: remote{'phase': 'local-remounting', 'value': False}{'phase': 'local-remounting', 'value': False}Passed
domain state regression 6: local{'phase': 'local-visible', 'value': True}{'phase': 'local-visible', 'value': True}Passed
domain state regression 7: remote{'phase': 'local-visible', 'value': False}{'phase': 'local-visible', 'value': False}Passed

SHA-256 / 34d7dd52f033b0404874ff518364a4e8195337bdeae5216b4e9ac52fb7855cab

Verification & scope

Stipulated single-notification state and policy model only. Event delivery and acknowledgements are explicit test inputs. No DOM, accessibility announcements, live timers, networking, actual rendering, or production-platform conformance is simulated. 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 2026-09-29T14:42:40.205450+00:00.

Case digest / 5e3f1aec35ceefe631b23e76b33db021a29d9eaedca15baa7b9b1753393a0060