FA-78116 / Subtitle cue timing / Open access

Proportional cue splitting: part weight · case 01

Empty fragments become zero-length cues.

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

ROOT CAUSE

Part weights have no minimum of one.

VERIFIED REPAIR

Weight each part by max(1, trimmed length).

Unsuccessful approach: Weighting untrimmed parts gives padded fragments too much screen time.

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=[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: part weight', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('regression variant: part weight', [[12345, 12352], [' there ', ' there ', 'xyz', '  ']], [[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]), ('partial repair probe: part weight', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('partial repair variant: part weight', [[1000, 1100], [' there ', 'friend']], [[1000, 1045, 'there'], [1045, 1100, 'friend']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary 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], ['xyz']], [[1000, 1007, 'xyz']]), ('normal control', [[1000, 1007], ['a', 'xyz', 'friend', 'a']], [[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']])], [('regression: part weight', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('regression variant: part weight', [[12345, 15346], ['a', '']], [[12345, 13845, 'a'], [13845, 15346, '']]), ('partial repair probe: part weight', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair variant: part weight', [[0, 2500], [' there ', 'Longer chunk of text']], [[0, 500, 'there'], [500, 2500, 'Longer chunk of text']]), ('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', [[0, 7], [' there ']], [[0, 7, 'there']]), ('normal control', [[1000, 1999], ['friend']], [[1000, 1999, 'friend']]), ('normal control', [[1000, 1999], ['xyz', 'friend']], [[1000, 1333, 'xyz'], [1333, 1999, 'friend']])], [('regression: part weight', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('regression variant: part weight', [[0, 2500], ['', 'ok ', '']], [[0, 625, ''], [625, 1875, 'ok'], [1875, 2500, '']]), ('partial repair probe: part weight', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair variant: part weight', [[1000, 3500], ['a', 'ok ', 'Longer chunk of text']], [[1000, 1108, 'a'], [1108, 1326, 'ok'], [1326, 3500, 'Longer chunk of text']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13345], ['Hello', 'friend', 'Hello']], [[12345, 12657, 'Hello'], [12657, 13032, 'friend'], [13032, 13345, 'Hello']]), ('normal control', [[12345, 15346], ['Hello']], [[12345, 15346, 'Hello']]), ('normal control', [[12345, 12352], ['xyz']], [[12345, 12352, 'xyz']])], [('regression: part weight', [[0, 7], ['  ', 'ok ', '  ', 'ok ']], [[0, 1, ''], [1, 3, 'ok'], [3, 4, ''], [4, 7, 'ok']]), ('regression variant: part weight', [[12345, 13345], ['  ', 'ok ']], [[12345, 12678, ''], [12678, 13345, 'ok']]), ('partial repair probe: part weight', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('partial repair variant: part weight', [[1000, 3500], ['a', 'ok ', 'Longer chunk of text']], [[1000, 1108, 'a'], [1108, 1326, 'ok'], [1326, 3500, 'Longer chunk of text']]), ('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, 12445], ['a']], [[12345, 12445, 'a']]), ('normal control', [[12345, 13345], ['xyz']], [[12345, 13345, 'xyz']]), ('normal control', [[12345, 12352], ['Longer chunk of text', 'a', 'xyz']], [[12345, 12350, 'Longer chunk of text'], [12350, 12351, 'a'], [12351, 12352, 'xyz']])], [('regression: part weight', [[1000, 2000], ['ok ', '', '']], [[1000, 1500, 'ok'], [1500, 1750, ''], [1750, 2000, '']]), ('regression variant: part weight', [[0, 100], ['', '', 'friend']], [[0, 12, ''], [12, 25, ''], [25, 100, 'friend']]), ('partial repair probe: part weight', [[1000, 1100], [' there ', 'ok ', 'Longer chunk of text']], [[1000, 1018, 'there'], [1018, 1025, 'ok'], [1025, 1100, 'Longer chunk of text']]), ('partial repair variant: part weight', [[12345, 13345], ['  ', 'ok ']], [[12345, 12678, ''], [12678, 13345, 'ok']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13344], ['Hello', 'friend', 'a']], [[12345, 12761, 'Hello'], [12761, 13260, 'friend'], [13260, 13344, 'a']]), ('normal control', [[12345, 13345], ['friend']], [[12345, 13345, 'friend']]), ('normal control', [[12345, 15346], ['xyz', 'Hello', 'a']], [[12345, 13345, 'xyz'], [13345, 15012, 'Hello'], [15012, 15346, '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 fixture	Actual	Expected	Outcome
regression: part weight	`[[0, 1000, 'a'], [1000, 1000, '']]`	`[[0, 500, 'a'], [500, 1000, '']]`	Failed
regression variant: part weight	`[[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12352, 'xyz'], [12352, 12352, '']]`	`[[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]`	Failed
partial repair probe: part weight	`[[0, 857, 'ok'], [857, 3001, 'there']]`	`[[0, 857, 'ok'], [857, 3001, 'there']]`	Passed
partial repair variant: part weight	`[[1000, 1045, 'there'], [1045, 1100, 'friend']]`	`[[1000, 1045, 'there'], [1045, 1100, 'friend']]`	Passed
boundary control	`[[0, 500, 'ab'], [500, 1000, 'cd']]`	`[[0, 500, 'ab'], [500, 1000, 'cd']]`	Passed
boundary 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, 1007, 'xyz']]`	`[[1000, 1007, '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 / e2ec26f43e367721ccc1939b3a7e40acca02f892e90841403e7b34e080de02cf

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)) 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: part weight', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('regression variant: part weight', [[12345, 12352], [' there ', ' there ', 'xyz', '  ']], [[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]), ('partial repair probe: part weight', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('partial repair variant: part weight', [[1000, 1100], [' there ', 'friend']], [[1000, 1045, 'there'], [1045, 1100, 'friend']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary 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], ['xyz']], [[1000, 1007, 'xyz']]), ('normal control', [[1000, 1007], ['a', 'xyz', 'friend', 'a']], [[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']])], [('regression: part weight', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('regression variant: part weight', [[12345, 15346], ['a', '']], [[12345, 13845, 'a'], [13845, 15346, '']]), ('partial repair probe: part weight', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair variant: part weight', [[0, 2500], [' there ', 'Longer chunk of text']], [[0, 500, 'there'], [500, 2500, 'Longer chunk of text']]), ('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', [[0, 7], [' there ']], [[0, 7, 'there']]), ('normal control', [[1000, 1999], ['friend']], [[1000, 1999, 'friend']]), ('normal control', [[1000, 1999], ['xyz', 'friend']], [[1000, 1333, 'xyz'], [1333, 1999, 'friend']])], [('regression: part weight', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('regression variant: part weight', [[0, 2500], ['', 'ok ', '']], [[0, 625, ''], [625, 1875, 'ok'], [1875, 2500, '']]), ('partial repair probe: part weight', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair variant: part weight', [[1000, 3500], ['a', 'ok ', 'Longer chunk of text']], [[1000, 1108, 'a'], [1108, 1326, 'ok'], [1326, 3500, 'Longer chunk of text']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13345], ['Hello', 'friend', 'Hello']], [[12345, 12657, 'Hello'], [12657, 13032, 'friend'], [13032, 13345, 'Hello']]), ('normal control', [[12345, 15346], ['Hello']], [[12345, 15346, 'Hello']]), ('normal control', [[12345, 12352], ['xyz']], [[12345, 12352, 'xyz']])], [('regression: part weight', [[0, 7], ['  ', 'ok ', '  ', 'ok ']], [[0, 1, ''], [1, 3, 'ok'], [3, 4, ''], [4, 7, 'ok']]), ('regression variant: part weight', [[12345, 13345], ['  ', 'ok ']], [[12345, 12678, ''], [12678, 13345, 'ok']]), ('partial repair probe: part weight', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('partial repair variant: part weight', [[1000, 3500], ['a', 'ok ', 'Longer chunk of text']], [[1000, 1108, 'a'], [1108, 1326, 'ok'], [1326, 3500, 'Longer chunk of text']]), ('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, 12445], ['a']], [[12345, 12445, 'a']]), ('normal control', [[12345, 13345], ['xyz']], [[12345, 13345, 'xyz']]), ('normal control', [[12345, 12352], ['Longer chunk of text', 'a', 'xyz']], [[12345, 12350, 'Longer chunk of text'], [12350, 12351, 'a'], [12351, 12352, 'xyz']])], [('regression: part weight', [[1000, 2000], ['ok ', '', '']], [[1000, 1500, 'ok'], [1500, 1750, ''], [1750, 2000, '']]), ('regression variant: part weight', [[0, 100], ['', '', 'friend']], [[0, 12, ''], [12, 25, ''], [25, 100, 'friend']]), ('partial repair probe: part weight', [[1000, 1100], [' there ', 'ok ', 'Longer chunk of text']], [[1000, 1018, 'there'], [1018, 1025, 'ok'], [1025, 1100, 'Longer chunk of text']]), ('partial repair variant: part weight', [[12345, 13345], ['  ', 'ok ']], [[12345, 12678, ''], [12678, 13345, 'ok']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13344], ['Hello', 'friend', 'a']], [[12345, 12761, 'Hello'], [12761, 13260, 'friend'], [13260, 13344, 'a']]), ('normal control', [[12345, 13345], ['friend']], [[12345, 13345, 'friend']]), ('normal control', [[12345, 15346], ['xyz', 'Hello', 'a']], [[12345, 13345, 'xyz'], [13345, 15012, 'Hello'], [15012, 15346, '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 fixture	Actual	Expected	Outcome
regression: part weight	`[[0, 500, 'a'], [500, 1000, '']]`	`[[0, 500, 'a'], [500, 1000, '']]`	Passed
regression variant: part weight	`[[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]`	`[[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]`	Passed
partial repair probe: part weight	`[[0, 900, 'ok'], [900, 3001, 'there']]`	`[[0, 857, 'ok'], [857, 3001, 'there']]`	Failed
partial repair variant: part weight	`[[1000, 1053, 'there'], [1053, 1100, 'friend']]`	`[[1000, 1045, 'there'], [1045, 1100, 'friend']]`	Failed
boundary control	`[[0, 500, 'ab'], [500, 1000, 'cd']]`	`[[0, 500, 'ab'], [500, 1000, 'cd']]`	Passed
boundary 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, 1007, 'xyz']]`	`[[1000, 1007, '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 / c06ffc50cb0c8b1c773f34165fabe894a301c3ddb20ee89eb33a5423d413d629

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: part weight', [[0, 1000], ['a', '']], [[0, 500, 'a'], [500, 1000, '']]), ('regression variant: part weight', [[12345, 12352], [' there ', ' there ', 'xyz', '  ']], [[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]), ('partial repair probe: part weight', [[0, 3001], ['ok ', ' there ']], [[0, 857, 'ok'], [857, 3001, 'there']]), ('partial repair variant: part weight', [[1000, 1100], [' there ', 'friend']], [[1000, 1045, 'there'], [1045, 1100, 'friend']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary 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], ['xyz']], [[1000, 1007, 'xyz']]), ('normal control', [[1000, 1007], ['a', 'xyz', 'friend', 'a']], [[1000, 1000, 'a'], [1000, 1002, 'xyz'], [1002, 1006, 'friend'], [1006, 1007, 'a']])], [('regression: part weight', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('regression variant: part weight', [[12345, 15346], ['a', '']], [[12345, 13845, 'a'], [13845, 15346, '']]), ('partial repair probe: part weight', [[1000, 1999], ['ok ', 'Hello']], [[1000, 1285, 'ok'], [1285, 1999, 'Hello']]), ('partial repair variant: part weight', [[0, 2500], [' there ', 'Longer chunk of text']], [[0, 500, 'there'], [500, 2500, 'Longer chunk of text']]), ('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', [[0, 7], [' there ']], [[0, 7, 'there']]), ('normal control', [[1000, 1999], ['friend']], [[1000, 1999, 'friend']]), ('normal control', [[1000, 1999], ['xyz', 'friend']], [[1000, 1333, 'xyz'], [1333, 1999, 'friend']])], [('regression: part weight', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('regression variant: part weight', [[0, 2500], ['', 'ok ', '']], [[0, 625, ''], [625, 1875, 'ok'], [1875, 2500, '']]), ('partial repair probe: part weight', [[1000, 1999], ['ok ', '  ', 'friend', 'ok ']], [[1000, 1181, 'ok'], [1181, 1272, ''], [1272, 1817, 'friend'], [1817, 1999, 'ok']]), ('partial repair variant: part weight', [[1000, 3500], ['a', 'ok ', 'Longer chunk of text']], [[1000, 1108, 'a'], [1108, 1326, 'ok'], [1326, 3500, 'Longer chunk of text']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13345], ['Hello', 'friend', 'Hello']], [[12345, 12657, 'Hello'], [12657, 13032, 'friend'], [13032, 13345, 'Hello']]), ('normal control', [[12345, 15346], ['Hello']], [[12345, 15346, 'Hello']]), ('normal control', [[12345, 12352], ['xyz']], [[12345, 12352, 'xyz']])], [('regression: part weight', [[0, 7], ['  ', 'ok ', '  ', 'ok ']], [[0, 1, ''], [1, 3, 'ok'], [3, 4, ''], [4, 7, 'ok']]), ('regression variant: part weight', [[12345, 13345], ['  ', 'ok ']], [[12345, 12678, ''], [12678, 13345, 'ok']]), ('partial repair probe: part weight', [[12345, 13344], ['ok ', 'ok ', '  ']], [[12345, 12744, 'ok'], [12744, 13144, 'ok'], [13144, 13344, '']]), ('partial repair variant: part weight', [[1000, 3500], ['a', 'ok ', 'Longer chunk of text']], [[1000, 1108, 'a'], [1108, 1326, 'ok'], [1326, 3500, 'Longer chunk of text']]), ('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, 12445], ['a']], [[12345, 12445, 'a']]), ('normal control', [[12345, 13345], ['xyz']], [[12345, 13345, 'xyz']]), ('normal control', [[12345, 12352], ['Longer chunk of text', 'a', 'xyz']], [[12345, 12350, 'Longer chunk of text'], [12350, 12351, 'a'], [12351, 12352, 'xyz']])], [('regression: part weight', [[1000, 2000], ['ok ', '', '']], [[1000, 1500, 'ok'], [1500, 1750, ''], [1750, 2000, '']]), ('regression variant: part weight', [[0, 100], ['', '', 'friend']], [[0, 12, ''], [12, 25, ''], [25, 100, 'friend']]), ('partial repair probe: part weight', [[1000, 1100], [' there ', 'ok ', 'Longer chunk of text']], [[1000, 1018, 'there'], [1018, 1025, 'ok'], [1025, 1100, 'Longer chunk of text']]), ('partial repair variant: part weight', [[12345, 13345], ['  ', 'ok ']], [[12345, 12678, ''], [12678, 13345, 'ok']]), ('boundary control', [[0, 1000], ['ab', 'cd']], [[0, 500, 'ab'], [500, 1000, 'cd']]), ('boundary control', [[0, 7], ['abc', 'de', 'f']], [[0, 3, 'abc'], [3, 5, 'de'], [5, 7, 'f']]), ('normal control', [[12345, 13344], ['Hello', 'friend', 'a']], [[12345, 12761, 'Hello'], [12761, 13260, 'friend'], [13260, 13344, 'a']]), ('normal control', [[12345, 13345], ['friend']], [[12345, 13345, 'friend']]), ('normal control', [[12345, 15346], ['xyz', 'Hello', 'a']], [[12345, 13345, 'xyz'], [13345, 15012, 'Hello'], [15012, 15346, '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 fixture	Actual	Expected	Outcome
regression: part weight	`[[0, 500, 'a'], [500, 1000, '']]`	`[[0, 500, 'a'], [500, 1000, '']]`	Passed
regression variant: part weight	`[[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]`	`[[12345, 12347, 'there'], [12347, 12350, 'there'], [12350, 12351, 'xyz'], [12351, 12352, '']]`	Passed
partial repair probe: part weight	`[[0, 857, 'ok'], [857, 3001, 'there']]`	`[[0, 857, 'ok'], [857, 3001, 'there']]`	Passed
partial repair variant: part weight	`[[1000, 1045, 'there'], [1045, 1100, 'friend']]`	`[[1000, 1045, 'there'], [1045, 1100, 'friend']]`	Passed
boundary control	`[[0, 500, 'ab'], [500, 1000, 'cd']]`	`[[0, 500, 'ab'], [500, 1000, 'cd']]`	Passed
boundary 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, 1007, 'xyz']]`	`[[1000, 1007, '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 / 40d9563b5b579dcc0d55702bde61399d231ad0e078f36f30b69404f61de6e4b0

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 2026-09-29T14:49:32.102439+00:00.

Case digest / 6ea514facee874674c012986b4e23b653162f30fd5177198ff4950fa340a823f