{"abstract":"Very high AMTI yields a base larger than AMTI itself.","category":"Tax bracket computation","checks":7,"contract":"solve(amti, regular_cents, status): stipulated AMT, whole dollars. Exemption: single 85700 (phase-out threshold 609350), mfj 133300 (threshold 1218700). The exemption is reduced by 25% of AMTI above the threshold, with the reduction rounded down to whole dollars, never below 0. Base = max(0, amti - exemption). Tentative minimum tax = 26% of base up to 232600 plus 28% of base above 232600 (in cents: dollars times percent). AMT = max(0, TMT - regular tax). Return [exemption, tmt_cents, amt_cents].","evaluation_group":"w2-tax_bracket_computation-alternative-minimum-tax","failed_approach":"Zeroing the exemption only above twice the threshold still leaves negative exemptions in between.","family":"w2-tax_bracket_computation-alternative-minimum-tax-exemption-floor","id":"FA-62536","implementations":{"attempt":{"sha256":"04076993a483e889b23881989a48c43f38d57d3d628e54ec295a50f404acaf07","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(amti, regular_cents, status):\n    ex, thr = {'single': (85700, 609350), 'mfj': (133300, 1218700)}[status]\n    if amti > thr: ex = 0 if amti > 2 * thr else ex - (amti - thr) // 4\n    base = max(0, amti - ex)\n    tmt = min(base, 232600) * 26 + max(0, base - 232600) * 28\n    return [ex, tmt, max(0, tmt - regular_cents)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncases = [[('regression exemption-floor 1', (1000000, 99999999, 'single'), [0, 27534800, 0]),\n  ('regression exemption-floor 2', (1526866, 0, 'single'), [0, 42287048, 42287048]),\n  ('partial repair guard 2', (1779652, 0, 'mfj'), [0, 49365056, 49365056]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084])],\n [('regression exemption-floor 1', (1694256, 2500000, 'single'), [0, 46973968, 44473968]),\n  ('regression exemption-floor 2', (1779652, 0, 'mfj'), [0, 49365056, 49365056]),\n  ('partial repair guard 1', (959971, 10000000, 'single'), [0, 26413988, 16413988]),\n  ('partial repair guard 2', (985171, 10000000, 'single'), [0, 27119588, 17119588]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400])],\n [('regression exemption-floor 1', (959971, 10000000, 'single'), [0, 26413988, 16413988]),\n  ('regression exemption-floor 2', (1689832, 2500000, 'single'), [0, 46850096, 44350096]),\n  ('partial repair guard 1', (1130943, 0, 'single'), [0, 31201204, 31201204]),\n  ('partial repair guard 2', (981886, 10000000, 'single'), [0, 27027608, 17027608]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736]),\n  ('control: no exemption left', (1000000, 99999999, 'single'), [0, 27534800, 0])],\n [('regression exemption-floor 1', (1444926, 0, 'single'), [0, 39992728, 39992728]),\n  ('regression exemption-floor 2', (1318587, 0, 'single'), [0, 36455236, 36455236]),\n  ('partial repair guard 1', (975205, 0, 'single'), [0, 26840540, 26840540]),\n  ('partial repair guard 2', (970054, 2500000, 'single'), [0, 26696312, 24196312]),\n  ('control: no exemption left', (1000000, 99999999, 'single'), [0, 27534800, 0]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500])],\n [('regression exemption-floor 1', (1233164, 34995277, 'single'), [0, 34063392, 0]),\n  ('regression exemption-floor 2', (1417848, 2500000, 'single'), [0, 39234544, 36734544]),\n  ('partial repair guard 1', (1068993, 10000000, 'single'), [0, 29466604, 19466604]),\n  ('partial repair guard 2', (1201655, 19779950, 'single'), [0, 33181140, 13401190]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736])]]\nfor label, args, expected in cases[N - 1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"cbeeffe2929f3240a18fe6c757580c60f0f5598f44bb7b9de715532f45246378","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(amti, regular_cents, status):\n    ex, thr = {'single': (85700, 609350), 'mfj': (133300, 1218700)}[status]\n    if amti > thr: ex = ex - (amti - thr) // 4\n    base = max(0, amti - ex)\n    tmt = min(base, 232600) * 26 + max(0, base - 232600) * 28\n    return [ex, tmt, max(0, tmt - regular_cents)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncases = [[('regression exemption-floor 1', (1000000, 99999999, 'single'), [0, 27534800, 0]),\n  ('regression exemption-floor 2', (1526866, 0, 'single'), [0, 42287048, 42287048]),\n  ('partial repair guard 2', (1779652, 0, 'mfj'), [0, 49365056, 49365056]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084])],\n [('regression exemption-floor 1', (1694256, 2500000, 'single'), [0, 46973968, 44473968]),\n  ('regression exemption-floor 2', (1779652, 0, 'mfj'), [0, 49365056, 49365056]),\n  ('partial repair guard 1', (959971, 10000000, 'single'), [0, 26413988, 16413988]),\n  ('partial repair guard 2', (985171, 10000000, 'single'), [0, 27119588, 17119588]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400])],\n [('regression exemption-floor 1', (959971, 10000000, 'single'), [0, 26413988, 16413988]),\n  ('regression exemption-floor 2', (1689832, 2500000, 'single'), [0, 46850096, 44350096]),\n  ('partial repair guard 1', (1130943, 0, 'single'), [0, 31201204, 31201204]),\n  ('partial repair guard 2', (981886, 10000000, 'single'), [0, 27027608, 17027608]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736]),\n  ('control: no exemption left', (1000000, 99999999, 'single'), [0, 27534800, 0])],\n [('regression exemption-floor 1', (1444926, 0, 'single'), [0, 39992728, 39992728]),\n  ('regression exemption-floor 2', (1318587, 0, 'single'), [0, 36455236, 36455236]),\n  ('partial repair guard 1', (975205, 0, 'single'), [0, 26840540, 26840540]),\n  ('partial repair guard 2', (970054, 2500000, 'single'), [0, 26696312, 24196312]),\n  ('control: no exemption left', (1000000, 99999999, 'single'), [0, 27534800, 0]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500])],\n [('regression exemption-floor 1', (1233164, 34995277, 'single'), [0, 34063392, 0]),\n  ('regression exemption-floor 2', (1417848, 2500000, 'single'), [0, 39234544, 36734544]),\n  ('partial repair guard 1', (1068993, 10000000, 'single'), [0, 29466604, 19466604]),\n  ('partial repair guard 2', (1201655, 19779950, 'single'), [0, 33181140, 13401190]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736])]]\nfor label, args, expected in cases[N - 1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"af1b4d3f3ee52630c67dc3dc7925a1ec7231bda4550196ac015e4dd3e9049e0f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(amti, regular_cents, status):\n    ex, thr = {'single': (85700, 609350), 'mfj': (133300, 1218700)}[status]\n    if amti > thr: ex = max(0, ex - (amti - thr) // 4)\n    base = max(0, amti - ex)\n    tmt = min(base, 232600) * 26 + max(0, base - 232600) * 28\n    return [ex, tmt, max(0, tmt - regular_cents)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncases = [[('regression exemption-floor 1', (1000000, 99999999, 'single'), [0, 27534800, 0]),\n  ('regression exemption-floor 2', (1526866, 0, 'single'), [0, 42287048, 42287048]),\n  ('partial repair guard 2', (1779652, 0, 'mfj'), [0, 49365056, 49365056]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084])],\n [('regression exemption-floor 1', (1694256, 2500000, 'single'), [0, 46973968, 44473968]),\n  ('regression exemption-floor 2', (1779652, 0, 'mfj'), [0, 49365056, 49365056]),\n  ('partial repair guard 1', (959971, 10000000, 'single'), [0, 26413988, 16413988]),\n  ('partial repair guard 2', (985171, 10000000, 'single'), [0, 27119588, 17119588]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400])],\n [('regression exemption-floor 1', (959971, 10000000, 'single'), [0, 26413988, 16413988]),\n  ('regression exemption-floor 2', (1689832, 2500000, 'single'), [0, 46850096, 44350096]),\n  ('partial repair guard 1', (1130943, 0, 'single'), [0, 31201204, 31201204]),\n  ('partial repair guard 2', (981886, 10000000, 'single'), [0, 27027608, 17027608]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736]),\n  ('control: no exemption left', (1000000, 99999999, 'single'), [0, 27534800, 0])],\n [('regression exemption-floor 1', (1444926, 0, 'single'), [0, 39992728, 39992728]),\n  ('regression exemption-floor 2', (1318587, 0, 'single'), [0, 36455236, 36455236]),\n  ('partial repair guard 1', (975205, 0, 'single'), [0, 26840540, 26840540]),\n  ('partial repair guard 2', (970054, 2500000, 'single'), [0, 26696312, 24196312]),\n  ('control: no exemption left', (1000000, 99999999, 'single'), [0, 27534800, 0]),\n  ('control: below exemption', (100000, 0, 'mfj'), [133300, 0, 0]),\n  ('control: odd excess', (609353, 5000000, 'single'), [85700, 14197084, 9197084]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500])],\n [('regression exemption-floor 1', (1233164, 34995277, 'single'), [0, 34063392, 0]),\n  ('regression exemption-floor 2', (1417848, 2500000, 'single'), [0, 39234544, 36734544]),\n  ('partial repair guard 1', (1068993, 10000000, 'single'), [0, 29466604, 19466604]),\n  ('partial repair guard 2', (1201655, 19779950, 'single'), [0, 33181140, 13401190]),\n  ('control: joint high', (1300000, 30000000, 'mfj'), [112975, 32771500, 2771500]),\n  ('control: rate break', (400000, 0, 'mfj'), [133300, 7002400, 7002400]),\n  ('control: moderate single', (200000, 2500000, 'single'), [85700, 2971800, 471800]),\n  ('control: partial phase-out', (700000, 0, 'single'), [63038, 17369736, 17369736])]]\nfor label, args, expected in cases[N - 1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"A deterministic, bounded teaching model with a stipulated toy contract; it makes no claim of conformance to any real regulation, standard, or institution's rules. 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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-tax_bracket_computation-alternative-minimum-tax-exemption-floor","generated_at":"2026-09-29T14:47:05.572601+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Tax computations hinge on which slice, threshold, ordering and rounding rule applies at each step; a misplaced boundary silently misstates liabilities.","repair":"Floor the exemption at 0.","root_cause":"The reduced exemption is not floored at 0.","sha256":"a718bdfb1c50da42dc9946867a2cafa256cbede811d4fb3e3209b8e1f9784cfe","title":"A fully phased-out exemption turns negative and inflates the AMT base · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.274,"exit_code":1,"observations":[{"actual":[-11962,27869736,0],"check":"regression exemption-floor 1","expected":[0,27534800,0],"passed":false},{"actual":[0,42287048,42287048],"check":"regression exemption-floor 2","expected":[0,42287048,42287048],"passed":true},{"actual":[-6938,49559320,49559320],"check":"partial repair guard 2","expected":[0,49365056,49365056],"passed":false},{"actual":[85700,2971800,471800],"check":"control: moderate single","expected":[85700,2971800,471800],"passed":true},{"actual":[63038,17369736,17369736],"check":"control: partial phase-out","expected":[63038,17369736,17369736],"passed":true},{"actual":[133300,0,0],"check":"control: below exemption","expected":[133300,0,0],"passed":true},{"actual":[85700,14197084,9197084],"check":"control: odd excess","expected":[85700,14197084,9197084],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression exemption-floor 1\", \"actual\": [-11962, 27869736, 0], \"expected\": [0, 27534800, 0], \"passed\": false}, {\"check\": \"regression exemption-floor 2\", \"actual\": [0, 42287048, 42287048], \"expected\": [0, 42287048, 42287048], \"passed\": true}, {\"check\": \"partial repair guard 2\", \"actual\": [-6938, 49559320, 49559320], \"expected\": [0, 49365056, 49365056], \"passed\": false}, {\"check\": \"control: moderate single\", \"actual\": [85700, 2971800, 471800], \"expected\": [85700, 2971800, 471800], \"passed\": true}, {\"check\": \"control: partial phase-out\", \"actual\": [63038, 17369736, 17369736], \"expected\": [63038, 17369736, 17369736], \"passed\": true}, {\"check\": \"control: below exemption\", \"actual\": [133300, 0, 0], \"expected\": [133300, 0, 0], \"passed\": true}, {\"check\": \"control: odd excess\", \"actual\": [85700, 14197084, 9197084], \"expected\": [85700, 14197084, 9197084], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.645,"exit_code":1,"observations":[{"actual":[-11962,27869736,0],"check":"regression exemption-floor 1","expected":[0,27534800,0],"passed":false},{"actual":[-143679,46310060,46310060],"check":"regression exemption-floor 2","expected":[0,42287048,42287048],"passed":false},{"actual":[-6938,49559320,49559320],"check":"partial repair guard 2","expected":[0,49365056,49365056],"passed":false},{"actual":[85700,2971800,471800],"check":"control: moderate single","expected":[85700,2971800,471800],"passed":true},{"actual":[63038,17369736,17369736],"check":"control: partial phase-out","expected":[63038,17369736,17369736],"passed":true},{"actual":[133300,0,0],"check":"control: below exemption","expected":[133300,0,0],"passed":true},{"actual":[85700,14197084,9197084],"check":"control: odd excess","expected":[85700,14197084,9197084],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression exemption-floor 1\", \"actual\": [-11962, 27869736, 0], \"expected\": [0, 27534800, 0], \"passed\": false}, {\"check\": \"regression exemption-floor 2\", \"actual\": [-143679, 46310060, 46310060], \"expected\": [0, 42287048, 42287048], \"passed\": false}, {\"check\": \"partial repair guard 2\", \"actual\": [-6938, 49559320, 49559320], \"expected\": [0, 49365056, 49365056], \"passed\": false}, {\"check\": \"control: moderate single\", \"actual\": [85700, 2971800, 471800], \"expected\": [85700, 2971800, 471800], \"passed\": true}, {\"check\": \"control: partial phase-out\", \"actual\": [63038, 17369736, 17369736], \"expected\": [63038, 17369736, 17369736], \"passed\": true}, {\"check\": \"control: below exemption\", \"actual\": [133300, 0, 0], \"expected\": [133300, 0, 0], \"passed\": true}, {\"check\": \"control: odd excess\", \"actual\": [85700, 14197084, 9197084], \"expected\": [85700, 14197084, 9197084], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":42.266,"exit_code":0,"observations":[{"actual":[0,27534800,0],"check":"regression exemption-floor 1","expected":[0,27534800,0],"passed":true},{"actual":[0,42287048,42287048],"check":"regression exemption-floor 2","expected":[0,42287048,42287048],"passed":true},{"actual":[0,49365056,49365056],"check":"partial repair guard 2","expected":[0,49365056,49365056],"passed":true},{"actual":[85700,2971800,471800],"check":"control: moderate single","expected":[85700,2971800,471800],"passed":true},{"actual":[63038,17369736,17369736],"check":"control: partial phase-out","expected":[63038,17369736,17369736],"passed":true},{"actual":[133300,0,0],"check":"control: below exemption","expected":[133300,0,0],"passed":true},{"actual":[85700,14197084,9197084],"check":"control: odd excess","expected":[85700,14197084,9197084],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression exemption-floor 1\", \"actual\": [0, 27534800, 0], \"expected\": [0, 27534800, 0], \"passed\": true}, {\"check\": \"regression exemption-floor 2\", \"actual\": [0, 42287048, 42287048], \"expected\": [0, 42287048, 42287048], \"passed\": true}, {\"check\": \"partial repair guard 2\", \"actual\": [0, 49365056, 49365056], \"expected\": [0, 49365056, 49365056], \"passed\": true}, {\"check\": \"control: moderate single\", \"actual\": [85700, 2971800, 471800], \"expected\": [85700, 2971800, 471800], \"passed\": true}, {\"check\": \"control: partial phase-out\", \"actual\": [63038, 17369736, 17369736], \"expected\": [63038, 17369736, 17369736], \"passed\": true}, {\"check\": \"control: below exemption\", \"actual\": [133300, 0, 0], \"expected\": [133300, 0, 0], \"passed\": true}, {\"check\": \"control: odd excess\", \"actual\": [85700, 14197084, 9197084], \"expected\": [85700, 14197084, 9197084], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}