{"abstract":"Filers just above the limit pay the full 5.5% surcharge.","category":"Tax bracket computation","checks":7,"contract":"solve(income_tax, joint): stipulated surcharge on income tax, in integer cents. The exemption limit is 1813000 (doubled for joint assessment). At or below it the surcharge is 0; above it the surcharge is the lesser of 5.5% of the income tax and 11.9% of the excess over the limit (a gliding zone), rounded down to cents.","contract_signature":"income_tax, joint","evaluation_group":"w2-tax_bracket_computation-surcharge-exemption-limit-glide","failed_approach":"Charging 11.9% of the excess without comparing to 5.5% of the tax over-charges high incomes.","family":"w2-tax_bracket_computation-surcharge-exemption-limit-glide-glide-base","id":"FA-62796","implementations":{"attempt":{"sha256":"e5faa92e65f925bc7cb926e30f3069ba270db0f8759e70a2e2bfad7012d9097c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(income_tax, joint):\n    thr = 1813000 * (2 if joint else 1)\n    if income_tax <= thr: return 0\n    soli = (income_tax - thr) * Fraction(119, 1000)\n    return int(soli)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncases = [[('regression glide-base 1', (1900000, False), 10353), ('regression glide-base 2', (3700000, True), 8806),\n  ('partial repair guard 1', (5000000, False), 275000), ('partial repair guard 2', (3626001, False), 199430),\n  ('control: at limit', (1813000, False), 0), ('control: joint below', (3000000, True), 0),\n  ('control: glide edge', (3300000, False), 176953)],\n [('regression glide-base 1', (3300000, False), 176953), ('regression glide-base 2', (1813009, False), 1),\n  ('partial repair guard 1', (3835420, False), 210948), ('partial repair guard 2', (3974588, False), 218602),\n  ('control: joint glide', (3700000, True), 8806), ('control: joint below', (3000000, True), 0),\n  ('control: at limit', (1813000, False), 0), ('control: gliding zone', (1900000, False), 10353)],\n [('regression glide-base 1', (1983210, False), 20254), ('regression glide-base 2', (1813001, False), 0),\n  ('partial repair guard 1', (3508965, False), 192993), ('partial repair guard 2', (3491244, False), 192018),\n  ('control: at limit', (1813000, False), 0), ('control: gliding zone', (1900000, False), 10353),\n  ('control: full rate', (5000000, False), 275000), ('control: joint glide', (3700000, True), 8806)],\n [('regression glide-base 1', (3626001, True), 0), ('regression glide-base 2', (4499538, True), 103951),\n  ('partial repair guard 1', (3409571, False), 187526), ('partial repair guard 2', (4398816, False), 241934),\n  ('control: joint glide', (3700000, True), 8806), ('control: joint below', (3000000, True), 0),\n  ('control: glide edge', (3300000, False), 176953), ('control: at limit', (1813000, False), 0)],\n [('regression glide-base 1', (3256603, False), 171788), ('regression glide-base 2', (2115665, False), 36017),\n  ('partial repair guard 1', (5112893, False), 281209), ('partial repair guard 2', (4374325, False), 240587),\n  ('control: at limit', (1813000, False), 0), ('control: gliding zone', (1900000, False), 10353),\n  ('control: full rate', (5000000, False), 275000), ('control: joint glide', (3700000, True), 8806)]]\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":"d2419577f3e31f3c700ece6b92a0c656589c852b34a9d52f1d1e42b95dcdac16","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(income_tax, joint):\n    thr = 1813000 * (2 if joint else 1)\n    if income_tax <= thr: return 0\n    soli = min(income_tax * Fraction(55, 1000), income_tax * Fraction(119, 1000))\n    return int(soli)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncases = [[('regression glide-base 1', (1900000, False), 10353), ('regression glide-base 2', (3700000, True), 8806),\n  ('partial repair guard 1', (5000000, False), 275000), ('partial repair guard 2', (3626001, False), 199430),\n  ('control: at limit', (1813000, False), 0), ('control: joint below', (3000000, True), 0),\n  ('control: glide edge', (3300000, False), 176953)],\n [('regression glide-base 1', (3300000, False), 176953), ('regression glide-base 2', (1813009, False), 1),\n  ('partial repair guard 1', (3835420, False), 210948), ('partial repair guard 2', (3974588, False), 218602),\n  ('control: joint glide', (3700000, True), 8806), ('control: joint below', (3000000, True), 0),\n  ('control: at limit', (1813000, False), 0), ('control: gliding zone', (1900000, False), 10353)],\n [('regression glide-base 1', (1983210, False), 20254), ('regression glide-base 2', (1813001, False), 0),\n  ('partial repair guard 1', (3508965, False), 192993), ('partial repair guard 2', (3491244, False), 192018),\n  ('control: at limit', (1813000, False), 0), ('control: gliding zone', (1900000, False), 10353),\n  ('control: full rate', (5000000, False), 275000), ('control: joint glide', (3700000, True), 8806)],\n [('regression glide-base 1', (3626001, True), 0), ('regression glide-base 2', (4499538, True), 103951),\n  ('partial repair guard 1', (3409571, False), 187526), ('partial repair guard 2', (4398816, False), 241934),\n  ('control: joint glide', (3700000, True), 8806), ('control: joint below', (3000000, True), 0),\n  ('control: glide edge', (3300000, False), 176953), ('control: at limit', (1813000, False), 0)],\n [('regression glide-base 1', (3256603, False), 171788), ('regression glide-base 2', (2115665, False), 36017),\n  ('partial repair guard 1', (5112893, False), 281209), ('partial repair guard 2', (4374325, False), 240587),\n  ('control: at limit', (1813000, False), 0), ('control: gliding zone', (1900000, False), 10353),\n  ('control: full rate', (5000000, False), 275000), ('control: joint glide', (3700000, True), 8806)]]\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-surcharge-exemption-limit-glide-glide-base","generated_at":"2026-09-29T14:47:08.031823+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.","root_cause":"The 11.9% cap is computed on the whole tax rather than on the excess over the limit.","sha256":"de4e8da1382f3f08840340a89b4a17a1304276c965547410450c742f933409b9","title":"The gliding cap is applied to the whole income tax · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":47.319,"exit_code":1,"observations":[{"actual":10353,"check":"regression glide-base 1","expected":10353,"passed":true},{"actual":8806,"check":"regression glide-base 2","expected":8806,"passed":true},{"actual":379253,"check":"partial repair guard 1","expected":275000,"passed":false},{"actual":215747,"check":"partial repair guard 2","expected":199430,"passed":false},{"actual":0,"check":"control: at limit","expected":0,"passed":true},{"actual":0,"check":"control: joint below","expected":0,"passed":true},{"actual":176953,"check":"control: glide edge","expected":176953,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression glide-base 1\", \"actual\": 10353, \"expected\": 10353, \"passed\": true}, {\"check\": \"regression glide-base 2\", \"actual\": 8806, \"expected\": 8806, \"passed\": true}, {\"check\": \"partial repair guard 1\", \"actual\": 379253, \"expected\": 275000, \"passed\": false}, {\"check\": \"partial repair guard 2\", \"actual\": 215747, \"expected\": 199430, \"passed\": false}, {\"check\": \"control: at limit\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"control: joint below\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"control: glide edge\", \"actual\": 176953, \"expected\": 176953, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":47.154,"exit_code":1,"observations":[{"actual":104500,"check":"regression glide-base 1","expected":10353,"passed":false},{"actual":203500,"check":"regression glide-base 2","expected":8806,"passed":false},{"actual":275000,"check":"partial repair guard 1","expected":275000,"passed":true},{"actual":199430,"check":"partial repair guard 2","expected":199430,"passed":true},{"actual":0,"check":"control: at limit","expected":0,"passed":true},{"actual":0,"check":"control: joint below","expected":0,"passed":true},{"actual":181500,"check":"control: glide edge","expected":176953,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression glide-base 1\", \"actual\": 104500, \"expected\": 10353, \"passed\": false}, {\"check\": \"regression glide-base 2\", \"actual\": 203500, \"expected\": 8806, \"passed\": false}, {\"check\": \"partial repair guard 1\", \"actual\": 275000, \"expected\": 275000, \"passed\": true}, {\"check\": \"partial repair guard 2\", \"actual\": 199430, \"expected\": 199430, \"passed\": true}, {\"check\": \"control: at limit\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"control: joint below\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"control: glide edge\", \"actual\": 181500, \"expected\": 176953, \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}