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FA-78136 / Subtitle cue timing / Open access

Proportional cue splitting: piece text trim · case 01

Split pieces show stray leading and trailing spaces.

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

ROOT CAUSE

The emitted text is the raw fragment.

VERIFIED REPAIR

Emit the trimmed fragment.

Unsuccessful approach: Trimming only the left side leaves trailing spaces in the piece text.

Case contract

Split cue [start,end] into len(parts) consecutive cues. Each part weighs max(1, len(part.strip())). Boundary after part k is start + floor(dur * cumulative_weight_k / total_weight); pieces are contiguous and the last ends at end. Output [s,e,part.strip()].

Why this case matters

Subtitle timing defects shift, hide or overlap captions that viewers depend on for comprehension and accessibility.

1 / The failure

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

N = 1
observations = []
def solve(cue, parts):
    start,end=cue
    w=[max(1,len(p.strip())) for p in parts]
    total=sum(w)
    dur=end-start
    out=[]
    acc=0
    prev=start
    for p,x in zip(parts,w):
        acc+=x
        b=start+dur*acc//total
        out.append([prev,b,p])
        prev=b
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: piece text trim', [[100, 1100], [' x ', 'y']], [[100, 600, 'x'], [600, 1100, 'y']]), ('regression variant: piece text trim', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair probe: piece text trim', [[0, 100], ['friend', 'ok ', 'ok ']], [[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]), ('partial repair variant: piece text trim', [[1000, 4001], ['friend', 'a', ' there ', 'a']], [[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, 'there'], [3770, 4001, 'a']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('normal control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[0, 2500], ['xyz']], [[0, 2500, 'xyz']]), ('normal control', [[1000, 1007], ['a', 'xyz', 'friend', 'a']], [[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']])], [('regression: piece text trim', [[0, 7], ['friend', 'Hello', 'ok ']], [[0, 3, 'friend'], [3, 5, 'Hello'], [5, 7, 'ok']]), ('regression variant: piece text trim', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair probe: piece text trim', [[0, 7], [' there ']], [[0, 7, 'there']]), ('partial repair variant: piece text trim', [[0, 7], ['  ', 'ok ', '  ', 'ok ']], [[0, 1, ''], [1, 3, 'ok'], [3, 4, ''], [4, 7, 'ok']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[1000, 1999], ['a']], [[1000, 1999, 'a']]), ('normal control', [[12345, 15346], ['a', '']], [[12345, 13845, 'a'], [13845, 15346, '']]), ('normal control', [[12345, 13345], ['']], [[12345, 13345, '']])], [('regression: piece text trim', [[0, 100], ['friend', 'ok ', 'ok ']], [[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]), ('regression variant: piece text trim', [[12345, 12352], ['  ']], [[12345, 12352, '']]), ('partial repair probe: piece text trim', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('partial repair variant: piece text trim', [[1000, 2000], ['ok ', '', '']], [[1000, 1500, 'ok'], [1500, 1750, ''], [1750, 2000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('normal control', [[12345, 12352], ['xyz', '']], [[12345, 12350, 'xyz'], [12350, 12352, '']]), ('normal control', [[12345, 13345], ['Hello', 'friend', 'Hello']], [[12345, 12657, 'Hello'], [12657, 13032, 'friend'], [13032, 13345, 'Hello']]), ('normal control', [[1000, 1007], ['Longer chunk of text', 'Hello']], [[1000, 1005, 'Longer chunk of text'], [1005, 1007, 'Hello']])], [('regression: piece text trim', [[0, 7], [' there ']], [[0, 7, 'there']]), ('regression variant: piece text trim', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('partial repair probe: piece text trim', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair variant: piece text trim', [[12345, 12352], [' there ', ' there ', 'xyz', '  ']], [[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('normal control', [[1000, 3500], ['xyz', 'a']], [[1000, 2875, 'xyz'], [2875, 3500, 'a']]), ('normal control', [[12345, 12352], ['']], [[12345, 12352, '']]), ('normal control', [[12345, 13345], ['', 'friend', 'a']], [[12345, 12470, ''], [12470, 13220, 'friend'], [13220, 13345, 'a']])], [('regression: piece text trim', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('regression variant: piece text trim', [[1000, 1100], [' there ', 'ok ', 'Longer chunk of text']], [[1000, 1018, 'there'], [1018, 1025, 'ok'], [1025, 1100, 'Longer chunk of text']]), ('partial repair probe: piece text trim', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair variant: piece text trim', [[1000, 1100], [' there ', 'friend']], [[1000, 1045, 'there'], [1045, 1100, 'friend']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13345], ['xyz']], [[12345, 13345, 'xyz']]), ('normal control', [[1000, 2000], ['Longer chunk of text', 'Longer chunk of text', 'Hello', '']], [[1000, 1434, 'Longer chunk of text'], [1434, 1869, 'Longer chunk of text'], [1869, 1978, 'Hello'], [1978, 2000, '']]), ('normal control', [[12345, 13344], ['Hello', 'friend', 'a']], [[12345, 12761, 'Hello'], [12761, 13260, 'friend'], [13260, 13344, 'a']])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
regression: piece text trim[[100, 600, ' x '], [600, 1100, 'y']][[100, 600, 'x'], [600, 1100, 'y']]Failed
regression variant: piece text trim[[1000, 1285, 'ok '], [1285, 1999, 'Hello']][[1000, 1285, 'ok'], [1285, 1999, 'Hello']]Failed
partial repair probe: piece text trim[[0, 60, 'friend'], [60, 80, 'ok '], [80, 100, 'ok ']][[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]Failed
partial repair variant: piece text trim[[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, ' there '], [3770, 4001, 'a']][[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, 'there'], [3770, 4001, 'a']]Failed
boundary control[[0, 500, 'ab'], [500, 1000, 'cd']][[0, 500, 'ab'], [500, 1000, 'cd']]Passed
boundary control[[0, 500, 'a'], [500, 1000, '']][[0, 500, 'a'], [500, 1000, '']]Passed
normal control[[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']][[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]Passed
normal control[[0, 2500, 'xyz']][[0, 2500, 'xyz']]Passed
normal control[[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']][[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']]Passed

SHA-256 / f8831dc43e3e35ca59def64afd3a2ff1360fd11f330ca421e01029284da4b7c2

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(cue, parts):
    start,end=cue
    w=[max(1,len(p.strip())) for p in parts]
    total=sum(w)
    dur=end-start
    out=[]
    acc=0
    prev=start
    for p,x in zip(parts,w):
        acc+=x
        b=start+dur*acc//total
        out.append([prev,b,p.lstrip()])
        prev=b
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: piece text trim', [[100, 1100], [' x ', 'y']], [[100, 600, 'x'], [600, 1100, 'y']]), ('regression variant: piece text trim', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair probe: piece text trim', [[0, 100], ['friend', 'ok ', 'ok ']], [[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]), ('partial repair variant: piece text trim', [[1000, 4001], ['friend', 'a', ' there ', 'a']], [[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, 'there'], [3770, 4001, 'a']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('normal control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[0, 2500], ['xyz']], [[0, 2500, 'xyz']]), ('normal control', [[1000, 1007], ['a', 'xyz', 'friend', 'a']], [[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']])], [('regression: piece text trim', [[0, 7], ['friend', 'Hello', 'ok ']], [[0, 3, 'friend'], [3, 5, 'Hello'], [5, 7, 'ok']]), ('regression variant: piece text trim', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair probe: piece text trim', [[0, 7], [' there ']], [[0, 7, 'there']]), ('partial repair variant: piece text trim', [[0, 7], ['  ', 'ok ', '  ', 'ok ']], [[0, 1, ''], [1, 3, 'ok'], [3, 4, ''], [4, 7, 'ok']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[1000, 1999], ['a']], [[1000, 1999, 'a']]), ('normal control', [[12345, 15346], ['a', '']], [[12345, 13845, 'a'], [13845, 15346, '']]), ('normal control', [[12345, 13345], ['']], [[12345, 13345, '']])], [('regression: piece text trim', [[0, 100], ['friend', 'ok ', 'ok ']], [[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]), ('regression variant: piece text trim', [[12345, 12352], ['  ']], [[12345, 12352, '']]), ('partial repair probe: piece text trim', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('partial repair variant: piece text trim', [[1000, 2000], ['ok ', '', '']], [[1000, 1500, 'ok'], [1500, 1750, ''], [1750, 2000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('normal control', [[12345, 12352], ['xyz', '']], [[12345, 12350, 'xyz'], [12350, 12352, '']]), ('normal control', [[12345, 13345], ['Hello', 'friend', 'Hello']], [[12345, 12657, 'Hello'], [12657, 13032, 'friend'], [13032, 13345, 'Hello']]), ('normal control', [[1000, 1007], ['Longer chunk of text', 'Hello']], [[1000, 1005, 'Longer chunk of text'], [1005, 1007, 'Hello']])], [('regression: piece text trim', [[0, 7], [' there ']], [[0, 7, 'there']]), ('regression variant: piece text trim', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('partial repair probe: piece text trim', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair variant: piece text trim', [[12345, 12352], [' there ', ' there ', 'xyz', '  ']], [[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('normal control', [[1000, 3500], ['xyz', 'a']], [[1000, 2875, 'xyz'], [2875, 3500, 'a']]), ('normal control', [[12345, 12352], ['']], [[12345, 12352, '']]), ('normal control', [[12345, 13345], ['', 'friend', 'a']], [[12345, 12470, ''], [12470, 13220, 'friend'], [13220, 13345, 'a']])], [('regression: piece text trim', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('regression variant: piece text trim', [[1000, 1100], [' there ', 'ok ', 'Longer chunk of text']], [[1000, 1018, 'there'], [1018, 1025, 'ok'], [1025, 1100, 'Longer chunk of text']]), ('partial repair probe: piece text trim', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair variant: piece text trim', [[1000, 1100], [' there ', 'friend']], [[1000, 1045, 'there'], [1045, 1100, 'friend']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13345], ['xyz']], [[12345, 13345, 'xyz']]), ('normal control', [[1000, 2000], ['Longer chunk of text', 'Longer chunk of text', 'Hello', '']], [[1000, 1434, 'Longer chunk of text'], [1434, 1869, 'Longer chunk of text'], [1869, 1978, 'Hello'], [1978, 2000, '']]), ('normal control', [[12345, 13344], ['Hello', 'friend', 'a']], [[12345, 12761, 'Hello'], [12761, 13260, 'friend'], [13260, 13344, 'a']])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
regression: piece text trim[[100, 600, 'x '], [600, 1100, 'y']][[100, 600, 'x'], [600, 1100, 'y']]Failed
regression variant: piece text trim[[1000, 1285, 'ok '], [1285, 1999, 'Hello']][[1000, 1285, 'ok'], [1285, 1999, 'Hello']]Failed
partial repair probe: piece text trim[[0, 60, 'friend'], [60, 80, 'ok '], [80, 100, 'ok ']][[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]Failed
partial repair variant: piece text trim[[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, 'there '], [3770, 4001, 'a']][[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, 'there'], [3770, 4001, 'a']]Failed
boundary control[[0, 500, 'ab'], [500, 1000, 'cd']][[0, 500, 'ab'], [500, 1000, 'cd']]Passed
boundary control[[0, 500, 'a'], [500, 1000, '']][[0, 500, 'a'], [500, 1000, '']]Passed
normal control[[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']][[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]Passed
normal control[[0, 2500, 'xyz']][[0, 2500, 'xyz']]Passed
normal control[[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']][[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']]Passed

SHA-256 / 4b48137bf385800043f35655980005aaa8d76468a850e1aa42a5e9ce0ebd4300

3 / The verified repair

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

N = 1
observations = []
def solve(cue, parts):
    start,end=cue
    w=[max(1,len(p.strip())) for p in parts]
    total=sum(w)
    dur=end-start
    out=[]
    acc=0
    prev=start
    for p,x in zip(parts,w):
        acc+=x
        b=start+dur*acc//total
        out.append([prev,b,p.strip()])
        prev=b
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: piece text trim', [[100, 1100], [' x ', 'y']], [[100, 600, 'x'], [600, 1100, 'y']]), ('regression variant: piece text trim', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair probe: piece text trim', [[0, 100], ['friend', 'ok ', 'ok ']], [[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]), ('partial repair variant: piece text trim', [[1000, 4001], ['friend', 'a', ' there ', 'a']], [[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, 'there'], [3770, 4001, 'a']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('normal control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[0, 2500], ['xyz']], [[0, 2500, 'xyz']]), ('normal control', [[1000, 1007], ['a', 'xyz', 'friend', 'a']], [[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']])], [('regression: piece text trim', [[0, 7], ['friend', 'Hello', 'ok ']], [[0, 3, 'friend'], [3, 5, 'Hello'], [5, 7, 'ok']]), ('regression variant: piece text trim', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair probe: piece text trim', [[0, 7], [' there ']], [[0, 7, 'there']]), ('partial repair variant: piece text trim', [[0, 7], ['  ', 'ok ', '  ', 'ok ']], [[0, 1, ''], [1, 3, 'ok'], [3, 4, ''], [4, 7, 'ok']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[1000, 1999], ['a']], [[1000, 1999, 'a']]), ('normal control', [[12345, 15346], ['a', '']], [[12345, 13845, 'a'], [13845, 15346, '']]), ('normal control', [[12345, 13345], ['']], [[12345, 13345, '']])], [('regression: piece text trim', [[0, 100], ['friend', 'ok ', 'ok ']], [[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]), ('regression variant: piece text trim', [[12345, 12352], ['  ']], [[12345, 12352, '']]), ('partial repair probe: piece text trim', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('partial repair variant: piece text trim', [[1000, 2000], ['ok ', '', '']], [[1000, 1500, 'ok'], [1500, 1750, ''], [1750, 2000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('normal control', [[12345, 12352], ['xyz', '']], [[12345, 12350, 'xyz'], [12350, 12352, '']]), ('normal control', [[12345, 13345], ['Hello', 'friend', 'Hello']], [[12345, 12657, 'Hello'], [12657, 13032, 'friend'], [13032, 13345, 'Hello']]), ('normal control', [[1000, 1007], ['Longer chunk of text', 'Hello']], [[1000, 1005, 'Longer chunk of text'], [1005, 1007, 'Hello']])], [('regression: piece text trim', [[0, 7], [' there ']], [[0, 7, 'there']]), ('regression variant: piece text trim', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('partial repair probe: piece text trim', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair variant: piece text trim', [[12345, 12352], [' there ', ' there ', 'xyz', '  ']], [[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('normal control', [[1000, 3500], ['xyz', 'a']], [[1000, 2875, 'xyz'], [2875, 3500, 'a']]), ('normal control', [[12345, 12352], ['']], [[12345, 12352, '']]), ('normal control', [[12345, 13345], ['', 'friend', 'a']], [[12345, 12470, ''], [12470, 13220, 'friend'], [13220, 13345, 'a']])], [('regression: piece text trim', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('regression variant: piece text trim', [[1000, 1100], [' there ', 'ok ', 'Longer chunk of text']], [[1000, 1018, 'there'], [1018, 1025, 'ok'], [1025, 1100, 'Longer chunk of text']]), ('partial repair probe: piece text trim', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair variant: piece text trim', [[1000, 1100], [' there ', 'friend']], [[1000, 1045, 'there'], [1045, 1100, 'friend']]), ('boundary control', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13345], ['xyz']], [[12345, 13345, 'xyz']]), ('normal control', [[1000, 2000], ['Longer chunk of text', 'Longer chunk of text', 'Hello', '']], [[1000, 1434, 'Longer chunk of text'], [1434, 1869, 'Longer chunk of text'], [1869, 1978, 'Hello'], [1978, 2000, '']]), ('normal control', [[12345, 13344], ['Hello', 'friend', 'a']], [[12345, 12761, 'Hello'], [12761, 13260, 'friend'], [13260, 13344, 'a']])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
regression: piece text trim[[100, 600, 'x'], [600, 1100, 'y']][[100, 600, 'x'], [600, 1100, 'y']]Passed
regression variant: piece text trim[[1000, 1285, 'ok'], [1285, 1999, 'Hello']][[1000, 1285, 'ok'], [1285, 1999, 'Hello']]Passed
partial repair probe: piece text trim[[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']][[0, 60, 'friend'], [60, 80, 'ok'], [80, 100, 'ok']]Passed
partial repair variant: piece text trim[[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, 'there'], [3770, 4001, 'a']][[1000, 2385, 'friend'], [2385, 2615, 'a'], [2615, 3770, 'there'], [3770, 4001, 'a']]Passed
boundary control[[0, 500, 'ab'], [500, 1000, 'cd']][[0, 500, 'ab'], [500, 1000, 'cd']]Passed
boundary control[[0, 500, 'a'], [500, 1000, '']][[0, 500, 'a'], [500, 1000, '']]Passed
normal control[[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']][[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]Passed
normal control[[0, 2500, 'xyz']][[0, 2500, 'xyz']]Passed
normal control[[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']][[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']]Passed

SHA-256 / f9a9ac5820863092b3d2743cef259f99ad8a6acd5df7cda235470356a371b9cb

Verification & scope

A deterministic bounded teaching model with a stipulated toy contract; it does not claim conformance to any subtitle standard. 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 2026-09-29T14:49:32.620895+00:00.

Case digest / d072fc0aa6146b3a1a6c3ae490b3a430eaed3dcbbfc867c8b4fea7329cdcacec