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FA-21456 / Assistive announcements / Open access

Canceling one language removes hard boundaries and other phrases · case 01

The announcement trace violates the stated sentence-packing contract.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Fault site: elif e[0]=='cancel': q=[x for x in q if x is None or x[0]!=e[1]] is implemented as elif e[0]=='cancel': q=[]

THE FAILURE

Fault site: elif e[0]=='cancel': q=[x for x in q if x is None or x[0]!=e[1]] is implemented as elif e[0]=='cancel': q=[]

Unsuccessful approach: The attempted repair substitutes elif e[0]=='cancel': q=[x for x in q if x is not None and x[0]!=e[1]] and still violates a regression oracle.

Case contract

Input operations configure character budget then append indivisible phrases [text,language]. Flush packs consecutive same-language phrases with one space while within budget. A phrase longer than budget is emitted alone intact. Language change always starts a new packet. Empty phrases are ignored. Break inserts hard boundary. Cancel removes queued phrases of one language. Returned packets are [language,text], queued phrase count and budget; flush consumes pending phrases.

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):
    budget=10; q=[]; out=[]
    for e in events:
        if e[0]=='budget': budget=max(1,e[1])
        elif e[0]=='phrase':
            if e[1]: q.append([e[2],e[1]])
        elif e[0]=='break': q.append(None)
        elif e[0]=='cancel': q=[]
        elif e[0]=='flush':
            current=None
            for row in q:
                if row is None:
                    if current is not None: out.append(current); current=None
                    continue
                if current is not None and current[0]==row[0] and len(current[1])+1+len(row[1])<=budget:
                    current[1]+=' '+row[1]
                else:
                    if current is not None: out.append(current)
                    current=list(row)
            if current is not None: out.append(current)
            q.clear()
    return [out,len(q),budget]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['budget',2*N+1],['phrase','a'*N,'en'],['phrase','b'*N,'en'],['phrase','c','en'],['flush']]", "[['budget',2*N],['phrase','a'*N,'en'],['phrase','b'*N,'en'],['flush']]", "[['budget',100],['phrase','hello'*N,'en-US'],['phrase','hi','en-GB'],['break'],['phrase','x','en-GB'],['flush']]", "[['phrase','a','en'],['break'],['phrase','b','en'],['phrase','non','fr'],['cancel','fr'],['flush']]", "[['budget',1],['phrase','oversize'*N,'en'],['flush']]", "[['budget',0],['phrase','','en'],['phrase','  ','en'],['flush']]", "[['flush'],['break'],['flush']]"]
expected = {1: [[[['en', 'a b'], ['en', 'c']], 0, 3], [[['en', 'a'], ['en', 'b']], 0, 2], [[['en-US', 'hello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]], 2: [[[['en', 'aa bb'], ['en', 'c']], 0, 5], [[['en', 'aa'], ['en', 'bb']], 0, 4], [[['en-US', 'hellohello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversizeoversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]], 3: [[[['en', 'aaa bbb'], ['en', 'c']], 0, 7], [[['en', 'aaa'], ['en', 'bbb']], 0, 6], [[['en-US', 'hellohellohello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversizeoversizeoversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]], 4: [[[['en', 'aaaa bbbb'], ['en', 'c']], 0, 9], [[['en', 'aaaa'], ['en', 'bbbb']], 0, 8], [[['en-US', 'hellohellohellohello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversizeoversizeoversizeoversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]], 5: [[[['en', 'aaaaa bbbbb'], ['en', 'c']], 0, 11], [[['en', 'aaaaa'], ['en', 'bbbbb']], 0, 10], [[['en-US', 'hellohellohellohellohello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversizeoversizeoversizeoversizeoversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]]}[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 fixtureActualExpectedOutcome
trace-1[[['en', 'a b'], ['en', 'c']], 0, 3][[['en', 'a b'], ['en', 'c']], 0, 3]Passed
trace-2[[['en', 'a'], ['en', 'b']], 0, 2][[['en', 'a'], ['en', 'b']], 0, 2]Passed
trace-3[[['en-US', 'hello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100][[['en-US', 'hello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100]Passed
trace-4[[], 0, 10][[['en', 'a'], ['en', 'b']], 0, 10]Failed
trace-5[[['en', 'oversize']], 0, 1][[['en', 'oversize']], 0, 1]Passed
trace-6[[['en', ' ']], 0, 1][[['en', ' ']], 0, 1]Passed
trace-7[[], 0, 10][[], 0, 10]Passed

SHA-256 / 4739996432b56248d2c32c2a7a669bdd43872a9d65a1a2be5f778179d8ef48a4

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(events):
    budget=10; q=[]; out=[]
    for e in events:
        if e[0]=='budget': budget=max(1,e[1])
        elif e[0]=='phrase':
            if e[1]: q.append([e[2],e[1]])
        elif e[0]=='break': q.append(None)
        elif e[0]=='cancel': q=[x for x in q if x is not None and x[0]!=e[1]]
        elif e[0]=='flush':
            current=None
            for row in q:
                if row is None:
                    if current is not None: out.append(current); current=None
                    continue
                if current is not None and current[0]==row[0] and len(current[1])+1+len(row[1])<=budget:
                    current[1]+=' '+row[1]
                else:
                    if current is not None: out.append(current)
                    current=list(row)
            if current is not None: out.append(current)
            q.clear()
    return [out,len(q),budget]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['budget',2*N+1],['phrase','a'*N,'en'],['phrase','b'*N,'en'],['phrase','c','en'],['flush']]", "[['budget',2*N],['phrase','a'*N,'en'],['phrase','b'*N,'en'],['flush']]", "[['budget',100],['phrase','hello'*N,'en-US'],['phrase','hi','en-GB'],['break'],['phrase','x','en-GB'],['flush']]", "[['phrase','a','en'],['break'],['phrase','b','en'],['phrase','non','fr'],['cancel','fr'],['flush']]", "[['budget',1],['phrase','oversize'*N,'en'],['flush']]", "[['budget',0],['phrase','','en'],['phrase','  ','en'],['flush']]", "[['flush'],['break'],['flush']]"]
expected = {1: [[[['en', 'a b'], ['en', 'c']], 0, 3], [[['en', 'a'], ['en', 'b']], 0, 2], [[['en-US', 'hello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]], 2: [[[['en', 'aa bb'], ['en', 'c']], 0, 5], [[['en', 'aa'], ['en', 'bb']], 0, 4], [[['en-US', 'hellohello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversizeoversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]], 3: [[[['en', 'aaa bbb'], ['en', 'c']], 0, 7], [[['en', 'aaa'], ['en', 'bbb']], 0, 6], [[['en-US', 'hellohellohello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversizeoversizeoversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]], 4: [[[['en', 'aaaa bbbb'], ['en', 'c']], 0, 9], [[['en', 'aaaa'], ['en', 'bbbb']], 0, 8], [[['en-US', 'hellohellohellohello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversizeoversizeoversizeoversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]], 5: [[[['en', 'aaaaa bbbbb'], ['en', 'c']], 0, 11], [[['en', 'aaaaa'], ['en', 'bbbbb']], 0, 10], [[['en-US', 'hellohellohellohellohello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100], [[['en', 'a'], ['en', 'b']], 0, 10], [[['en', 'oversizeoversizeoversizeoversizeoversize']], 0, 1], [[['en', '  ']], 0, 1], [[], 0, 10]]}[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 fixtureActualExpectedOutcome
trace-1[[['en', 'a b'], ['en', 'c']], 0, 3][[['en', 'a b'], ['en', 'c']], 0, 3]Passed
trace-2[[['en', 'a'], ['en', 'b']], 0, 2][[['en', 'a'], ['en', 'b']], 0, 2]Passed
trace-3[[['en-US', 'hello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100][[['en-US', 'hello'], ['en-GB', 'hi'], ['en-GB', 'x']], 0, 100]Passed
trace-4[[['en', 'a b']], 0, 10][[['en', 'a'], ['en', 'b']], 0, 10]Failed
trace-5[[['en', 'oversize']], 0, 1][[['en', 'oversize']], 0, 1]Passed
trace-6[[['en', ' ']], 0, 1][[['en', ' ']], 0, 1]Passed
trace-7[[], 0, 10][[], 0, 10]Passed

SHA-256 / d5c9bcb5b116203e612c333ec9ce5e8014c847144baa59854418c5899bd387fe

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 7 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

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 2026-09-29T14:40:29.217011+00:00.

Case digest / 34efbb8117b76da6d3f86983cbd70f2a1985f1dc828b19a262c7e9e8971cfd5a