FA-21176 / Assistive announcements / Open access
Emergency message is lost while quiet is active · case 01
The announcement trace violates the stated quiet-session contract.
ROOT CAUSE
Fault site: if e[3]=='emergency': out.append([e[1],e[2],1]) is implemented as if e[3]=='emergency': pass
VERIFIED REPAIR
Restore the stated transition: if e[3]=='emergency': out.append([e[1],e[2],1])
Unsuccessful approach: The attempted repair substitutes if e[3]=='emergency' and not depth: out.append([e[1],e[2],1]) and still violates a regression oracle.
Case contract
Quiet nesting is a counter. Enter increments; leave decrements without going negative. Ordinary messages during quiet replace a per-topic summary [latest,count], emergency speech always emits immediately. Final leave emits summaries in topic first-seen order as [topic,latest,count]. Remove-topic discards only that summary. Reset quiet silently discards backlog. Ordinary speech outside quiet emits directly with count1. Report output, nesting and pending summaries.
Why this case matters
Deterministic controlled model of assistive announcement delivery.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(events):
depth=0; pending={}; out=[]
for e in events:
if e[0]=='enter': depth+=1
elif e[0]=='leave':
was=depth; depth=max(0,depth-1)
if was>0 and depth==0:
out.extend([[k,v[0],v[1]] for k,v in pending.items()])
pending.clear()
elif e[0]=='reset': depth=0; pending.clear()
elif e[0]=='remove': pending.pop(e[1],None)
elif e[0]=='message':
if e[3]=='emergency': pass
elif depth:
old=pending.get(e[1],['',0])
pending[e[1]]=[e[2],old[1]+1]
else: out.append([e[1],e[2],1])
return [out,depth,[[k]+v for k,v in pending.items()]]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['enter'],['enter'],['message','a','first'*N,'normal'],['leave']]", "[['enter'],['message','z','old','normal'],['message','a','a'*N,'normal'],['message','z','new','normal'],['leave'],['enter'],['leave']]", "[['enter'],['message','a','urgent'*N,'emergency']]", "[['enter'],['message','a','urgent'*N,'emergency'],['message','b','deferred','normal'],['leave']]", "[['enter'],['message','a','a'*N,'normal'],['message','b','b','normal'],['remove','a']]", "[['enter'],['message','a','x'*N,'normal'],['reset']]", "[['message','a','direct'*N,'normal'],['leave'],['leave']]", "[['enter'],['message','a','x'*N,'normal'],['leave'],['leave']]"]
expected = {1: [[[], 1, [['a', 'first', 1]]], [[['z', 'new', 2], ['a', 'a', 1]], 0, []], [[['a', 'urgent', 1]], 1, []], [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'direct', 1]], 0, []], [[['a', 'x', 1]], 0, []]], 2: [[[], 1, [['a', 'firstfirst', 1]]], [[['z', 'new', 2], ['a', 'aa', 1]], 0, []], [[['a', 'urgenturgent', 1]], 1, []], [[['a', 'urgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirect', 1]], 0, []], [[['a', 'xx', 1]], 0, []]], 3: [[[], 1, [['a', 'firstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaa', 1]], 0, []], [[['a', 'urgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirect', 1]], 0, []], [[['a', 'xxx', 1]], 0, []]], 4: [[[], 1, [['a', 'firstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirect', 1]], 0, []], [[['a', 'xxxx', 1]], 0, []]], 5: [[[], 1, [['a', 'firstfirstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirectdirect', 1]], 0, []], [[['a', 'xxxxx', 1]], 0, []]]}[N]
for i, expression in enumerate(fixtures):
check("trace-"+str(i+1), solve(eval(expression)), expected[i])
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 |
|---|---|---|---|
| trace-1 | [[], 1, [['a', 'first', 1]]] | [[], 1, [['a', 'first', 1]]] | Passed |
| trace-2 | [[['z', 'new', 2], ['a', 'a', 1]], 0, []] | [[['z', 'new', 2], ['a', 'a', 1]], 0, []] | Passed |
| trace-3 | [[], 1, []] | [[['a', 'urgent', 1]], 1, []] | Failed |
| trace-4 | [[['b', 'deferred', 1]], 0, []] | [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []] | Failed |
| trace-5 | [[], 1, [['b', 'b', 1]]] | [[], 1, [['b', 'b', 1]]] | Passed |
| trace-6 | [[], 0, []] | [[], 0, []] | Passed |
| trace-7 | [[['a', 'direct', 1]], 0, []] | [[['a', 'direct', 1]], 0, []] | Passed |
| trace-8 | [[['a', 'x', 1]], 0, []] | [[['a', 'x', 1]], 0, []] | Passed |
SHA-256 / 95f4f53649f4d38971ae02ef0d9ceb649e2bab6cf7a1a2c3c43599266ed30282
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(events):
depth=0; pending={}; out=[]
for e in events:
if e[0]=='enter': depth+=1
elif e[0]=='leave':
was=depth; depth=max(0,depth-1)
if was>0 and depth==0:
out.extend([[k,v[0],v[1]] for k,v in pending.items()])
pending.clear()
elif e[0]=='reset': depth=0; pending.clear()
elif e[0]=='remove': pending.pop(e[1],None)
elif e[0]=='message':
if e[3]=='emergency' and not depth: out.append([e[1],e[2],1])
elif depth:
old=pending.get(e[1],['',0])
pending[e[1]]=[e[2],old[1]+1]
else: out.append([e[1],e[2],1])
return [out,depth,[[k]+v for k,v in pending.items()]]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['enter'],['enter'],['message','a','first'*N,'normal'],['leave']]", "[['enter'],['message','z','old','normal'],['message','a','a'*N,'normal'],['message','z','new','normal'],['leave'],['enter'],['leave']]", "[['enter'],['message','a','urgent'*N,'emergency']]", "[['enter'],['message','a','urgent'*N,'emergency'],['message','b','deferred','normal'],['leave']]", "[['enter'],['message','a','a'*N,'normal'],['message','b','b','normal'],['remove','a']]", "[['enter'],['message','a','x'*N,'normal'],['reset']]", "[['message','a','direct'*N,'normal'],['leave'],['leave']]", "[['enter'],['message','a','x'*N,'normal'],['leave'],['leave']]"]
expected = {1: [[[], 1, [['a', 'first', 1]]], [[['z', 'new', 2], ['a', 'a', 1]], 0, []], [[['a', 'urgent', 1]], 1, []], [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'direct', 1]], 0, []], [[['a', 'x', 1]], 0, []]], 2: [[[], 1, [['a', 'firstfirst', 1]]], [[['z', 'new', 2], ['a', 'aa', 1]], 0, []], [[['a', 'urgenturgent', 1]], 1, []], [[['a', 'urgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirect', 1]], 0, []], [[['a', 'xx', 1]], 0, []]], 3: [[[], 1, [['a', 'firstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaa', 1]], 0, []], [[['a', 'urgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirect', 1]], 0, []], [[['a', 'xxx', 1]], 0, []]], 4: [[[], 1, [['a', 'firstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirect', 1]], 0, []], [[['a', 'xxxx', 1]], 0, []]], 5: [[[], 1, [['a', 'firstfirstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirectdirect', 1]], 0, []], [[['a', 'xxxxx', 1]], 0, []]]}[N]
for i, expression in enumerate(fixtures):
check("trace-"+str(i+1), solve(eval(expression)), expected[i])
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 |
|---|---|---|---|
| trace-1 | [[], 1, [['a', 'first', 1]]] | [[], 1, [['a', 'first', 1]]] | Passed |
| trace-2 | [[['z', 'new', 2], ['a', 'a', 1]], 0, []] | [[['z', 'new', 2], ['a', 'a', 1]], 0, []] | Passed |
| trace-3 | [[], 1, [['a', 'urgent', 1]]] | [[['a', 'urgent', 1]], 1, []] | Failed |
| trace-4 | [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []] | [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []] | Passed |
| trace-5 | [[], 1, [['b', 'b', 1]]] | [[], 1, [['b', 'b', 1]]] | Passed |
| trace-6 | [[], 0, []] | [[], 0, []] | Passed |
| trace-7 | [[['a', 'direct', 1]], 0, []] | [[['a', 'direct', 1]], 0, []] | Passed |
| trace-8 | [[['a', 'x', 1]], 0, []] | [[['a', 'x', 1]], 0, []] | Passed |
SHA-256 / e951bfb16aec879ad1c2d8690b64b8335002a8250e1737e7967115b0b8f5692b
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(events):
depth=0; pending={}; out=[]
for e in events:
if e[0]=='enter': depth+=1
elif e[0]=='leave':
was=depth; depth=max(0,depth-1)
if was>0 and depth==0:
out.extend([[k,v[0],v[1]] for k,v in pending.items()])
pending.clear()
elif e[0]=='reset': depth=0; pending.clear()
elif e[0]=='remove': pending.pop(e[1],None)
elif e[0]=='message':
if e[3]=='emergency': out.append([e[1],e[2],1])
elif depth:
old=pending.get(e[1],['',0])
pending[e[1]]=[e[2],old[1]+1]
else: out.append([e[1],e[2],1])
return [out,depth,[[k]+v for k,v in pending.items()]]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['enter'],['enter'],['message','a','first'*N,'normal'],['leave']]", "[['enter'],['message','z','old','normal'],['message','a','a'*N,'normal'],['message','z','new','normal'],['leave'],['enter'],['leave']]", "[['enter'],['message','a','urgent'*N,'emergency']]", "[['enter'],['message','a','urgent'*N,'emergency'],['message','b','deferred','normal'],['leave']]", "[['enter'],['message','a','a'*N,'normal'],['message','b','b','normal'],['remove','a']]", "[['enter'],['message','a','x'*N,'normal'],['reset']]", "[['message','a','direct'*N,'normal'],['leave'],['leave']]", "[['enter'],['message','a','x'*N,'normal'],['leave'],['leave']]"]
expected = {1: [[[], 1, [['a', 'first', 1]]], [[['z', 'new', 2], ['a', 'a', 1]], 0, []], [[['a', 'urgent', 1]], 1, []], [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'direct', 1]], 0, []], [[['a', 'x', 1]], 0, []]], 2: [[[], 1, [['a', 'firstfirst', 1]]], [[['z', 'new', 2], ['a', 'aa', 1]], 0, []], [[['a', 'urgenturgent', 1]], 1, []], [[['a', 'urgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirect', 1]], 0, []], [[['a', 'xx', 1]], 0, []]], 3: [[[], 1, [['a', 'firstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaa', 1]], 0, []], [[['a', 'urgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirect', 1]], 0, []], [[['a', 'xxx', 1]], 0, []]], 4: [[[], 1, [['a', 'firstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirect', 1]], 0, []], [[['a', 'xxxx', 1]], 0, []]], 5: [[[], 1, [['a', 'firstfirstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirectdirect', 1]], 0, []], [[['a', 'xxxxx', 1]], 0, []]]}[N]
for i, expression in enumerate(fixtures):
check("trace-"+str(i+1), solve(eval(expression)), expected[i])
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 |
|---|---|---|---|
| trace-1 | [[], 1, [['a', 'first', 1]]] | [[], 1, [['a', 'first', 1]]] | Passed |
| trace-2 | [[['z', 'new', 2], ['a', 'a', 1]], 0, []] | [[['z', 'new', 2], ['a', 'a', 1]], 0, []] | Passed |
| trace-3 | [[['a', 'urgent', 1]], 1, []] | [[['a', 'urgent', 1]], 1, []] | Passed |
| trace-4 | [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []] | [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []] | Passed |
| trace-5 | [[], 1, [['b', 'b', 1]]] | [[], 1, [['b', 'b', 1]]] | Passed |
| trace-6 | [[], 0, []] | [[], 0, []] | Passed |
| trace-7 | [[['a', 'direct', 1]], 0, []] | [[['a', 'direct', 1]], 0, []] | Passed |
| trace-8 | [[['a', 'x', 1]], 0, []] | [[['a', 'x', 1]], 0, []] | Passed |
SHA-256 / 1031369a1981ec50576770d1159fc7128c41c2f8c089569f3676f2f11a9da2b7
Verification & scope
Stipulated bounded policy, not a browser, speech engine, platform API, or standards conformance claim. 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 2026-09-29T14:40:26.051984+00:00.
Case digest / 1db55b5b40dd24a3de7a109116504534f53bde079bd03d774a34b44269f8beb3