{"abstract":"Relief grows as profits rise, so companies near the upper limit pay less than at the lower limit.","category":"Tax bracket computation","checks":6,"contract":"solve(profits, dividends, associates, days): stipulated small-profits relief. Limits L = 50000 and U = 250000 are divided by (associates + 1) and prorated by days/365 (exact fractions). Augmented profits A = profits + dividends decide the band: A <= L taxes profits N at 19%; A >= U at 25%; otherwise tax = 25% of N minus 3/200 * (U - A) * N / A. Return integer cents rounded half-up.","contract_signature":"profits, dividends, associates, days","evaluation_group":"w2-tax_bracket_computation-marginal-relief-band","failed_approach":"A constant relief based on (U - L) ignores where the company sits in the band.","family":"w2-tax_bracket_computation-marginal-relief-band-relief-distance","id":"FA-62576","implementations":{"attempt":{"sha256":"07f10ed46a4913fc07ddbe16918735ce67c335b96bbf2820ebf5927e6ab0366f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(profits, dividends, associates, days):\n    def prog(x, br):\n        tax, lower = Fraction(0), 0\n        for upper, rate in br:\n            top = x if upper is None else min(x, upper)\n            if top > lower: tax += (top - lower) * Fraction(rate) / 100\n            if upper is None or x <= upper: break\n            lower = upper\n        return tax\n    def cents(v):\n        v = v * 100\n        return int(v + Fraction(1, 2)) if v >= 0 else -int(-v + Fraction(1, 2))\n    \n    div = associates + 1\n    L = Fraction(50000 * days, 365 * div)\n    U = Fraction(250000 * days, 365 * div)\n    A = profits + dividends\n    N = Fraction(profits)\n    if A <= L: tax = N * 19 / 100\n    elif A >= U: tax = N * 25 / 100\n    else: tax = N * 25 / 100 - Fraction(3, 200) * (U - L) * N / A\n    return cents(tax)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncases = [[('regression relief-distance 1', (100000, 0, 0, 365), 2275000),\n  ('regression relief-distance 2', (60000, 0, 1, 365), 1402500), ('control: small profits', (40000, 0, 0, 365), 760000),\n  ('control: main rate', (300000, 0, 0, 365), 7500000), ('control: with dividends', (100000, 25000, 0, 365), 2350000),\n  ('control: short period', (30000, 0, 0, 181), 609041)],\n [('regression relief-distance 1', (100000, 25000, 0, 365), 2350000),\n  ('regression relief-distance 2', (30000, 0, 0, 181), 609041),\n  ('control: associated company', (60000, 0, 1, 365), 1402500),\n  ('control: two associates short', (70000, 5000, 2, 200), 1750000),\n  ('control: dividends push to main rate', (200000, 60000, 0, 365), 5000000),\n  ('control: small profits', (40000, 0, 0, 365), 760000)],\n [('regression relief-distance 1', (100000, 5000, 1, 365), 2471429),\n  ('regression relief-distance 2', (50000, 25000, 0, 365), 1075000),\n  ('control: two associates short', (70000, 5000, 2, 200), 1750000),\n  ('control: dividends push to main rate', (200000, 60000, 0, 365), 5000000),\n  ('control: small profits', (40000, 0, 0, 365), 760000), ('control: relief zone', (100000, 0, 0, 365), 2275000)],\n [('regression relief-distance 1', (100000, 5000, 0, 300), 2356458),\n  ('regression relief-distance 2', (50000, 60000, 0, 365), 1154545),\n  ('control: relief zone', (100000, 0, 0, 365), 2275000), ('control: main rate', (300000, 0, 0, 365), 7500000),\n  ('control: associated company', (60000, 0, 1, 365), 1402500),\n  ('control: with dividends', (100000, 25000, 0, 365), 2350000)],\n [('regression relief-distance 1', (30000, 5000, 0, 200), 618875),\n  ('regression relief-distance 2', (50000, 0, 1, 300), 1170890),\n  ('control: with dividends', (100000, 25000, 0, 365), 2350000), ('control: short period', (30000, 0, 0, 181), 609041),\n  ('control: two associates short', (70000, 5000, 2, 200), 1750000),\n  ('control: dividends push to main rate', (200000, 60000, 0, 365), 5000000)]]\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":"926fb3b0d44451d586797c33b33fb4343e4d86f252c74c5dfacfed6ea928655c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(profits, dividends, associates, days):\n    def prog(x, br):\n        tax, lower = Fraction(0), 0\n        for upper, rate in br:\n            top = x if upper is None else min(x, upper)\n            if top > lower: tax += (top - lower) * Fraction(rate) / 100\n            if upper is None or x <= upper: break\n            lower = upper\n        return tax\n    def cents(v):\n        v = v * 100\n        return int(v + Fraction(1, 2)) if v >= 0 else -int(-v + Fraction(1, 2))\n    \n    div = associates + 1\n    L = Fraction(50000 * days, 365 * div)\n    U = Fraction(250000 * days, 365 * div)\n    A = profits + dividends\n    N = Fraction(profits)\n    if A <= L: tax = N * 19 / 100\n    elif A >= U: tax = N * 25 / 100\n    else: tax = N * 25 / 100 - Fraction(3, 200) * (A - L) * N / A\n    return cents(tax)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncases = [[('regression relief-distance 1', (100000, 0, 0, 365), 2275000),\n  ('regression relief-distance 2', (60000, 0, 1, 365), 1402500), ('control: small profits', (40000, 0, 0, 365), 760000),\n  ('control: main rate', (300000, 0, 0, 365), 7500000), ('control: with dividends', (100000, 25000, 0, 365), 2350000),\n  ('control: short period', (30000, 0, 0, 181), 609041)],\n [('regression relief-distance 1', (100000, 25000, 0, 365), 2350000),\n  ('regression relief-distance 2', (30000, 0, 0, 181), 609041),\n  ('control: associated company', (60000, 0, 1, 365), 1402500),\n  ('control: two associates short', (70000, 5000, 2, 200), 1750000),\n  ('control: dividends push to main rate', (200000, 60000, 0, 365), 5000000),\n  ('control: small profits', (40000, 0, 0, 365), 760000)],\n [('regression relief-distance 1', (100000, 5000, 1, 365), 2471429),\n  ('regression relief-distance 2', (50000, 25000, 0, 365), 1075000),\n  ('control: two associates short', (70000, 5000, 2, 200), 1750000),\n  ('control: dividends push to main rate', (200000, 60000, 0, 365), 5000000),\n  ('control: small profits', (40000, 0, 0, 365), 760000), ('control: relief zone', (100000, 0, 0, 365), 2275000)],\n [('regression relief-distance 1', (100000, 5000, 0, 300), 2356458),\n  ('regression relief-distance 2', (50000, 60000, 0, 365), 1154545),\n  ('control: relief zone', (100000, 0, 0, 365), 2275000), ('control: main rate', (300000, 0, 0, 365), 7500000),\n  ('control: associated company', (60000, 0, 1, 365), 1402500),\n  ('control: with dividends', (100000, 25000, 0, 365), 2350000)],\n [('regression relief-distance 1', (30000, 5000, 0, 200), 618875),\n  ('regression relief-distance 2', (50000, 0, 1, 300), 1170890),\n  ('control: with dividends', (100000, 25000, 0, 365), 2350000), ('control: short period', (30000, 0, 0, 181), 609041),\n  ('control: two associates short', (70000, 5000, 2, 200), 1750000),\n  ('control: dividends push to main rate', (200000, 60000, 0, 365), 5000000)]]\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-marginal-relief-band-relief-distance","generated_at":"2026-09-29T14:47:05.965633+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 relief uses (A - L) instead of (U - A).","sha256":"92e4d32c3a4f741989335ad3883a721904ccb60ddda7f1119dc8071c3e7f16ef","title":"Marginal relief is measured from the lower limit instead of the upper limit · 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":44.764,"exit_code":1,"observations":[{"actual":2200000,"check":"regression relief-distance 1","expected":2275000,"passed":false},{"actual":1350000,"check":"regression relief-distance 2","expected":1402500,"passed":false},{"actual":760000,"check":"control: small profits","expected":760000,"passed":true},{"actual":7500000,"check":"control: main rate","expected":7500000,"passed":true},{"actual":2260000,"check":"control: with dividends","expected":2350000,"passed":false},{"actual":601233,"check":"control: short period","expected":609041,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression relief-distance 1\", \"actual\": 2200000, \"expected\": 2275000, \"passed\": false}, {\"check\": \"regression relief-distance 2\", \"actual\": 1350000, \"expected\": 1402500, \"passed\": false}, {\"check\": \"control: small profits\", \"actual\": 760000, \"expected\": 760000, \"passed\": true}, {\"check\": \"control: main rate\", \"actual\": 7500000, \"expected\": 7500000, \"passed\": true}, {\"check\": \"control: with dividends\", \"actual\": 2260000, \"expected\": 2350000, \"passed\": false}, {\"check\": \"control: short period\", \"actual\": 601233, \"expected\": 609041, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":43.311,"exit_code":1,"observations":[{"actual":2425000,"check":"regression relief-distance 1","expected":2275000,"passed":false},{"actual":1447500,"check":"regression relief-distance 2","expected":1402500,"passed":false},{"actual":760000,"check":"control: small profits","expected":760000,"passed":true},{"actual":7500000,"check":"control: main rate","expected":7500000,"passed":true},{"actual":2410000,"check":"control: with dividends","expected":2350000,"passed":false},{"actual":742192,"check":"control: short period","expected":609041,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression relief-distance 1\", \"actual\": 2425000, \"expected\": 2275000, \"passed\": false}, {\"check\": \"regression relief-distance 2\", \"actual\": 1447500, \"expected\": 1402500, \"passed\": false}, {\"check\": \"control: small profits\", \"actual\": 760000, \"expected\": 760000, \"passed\": true}, {\"check\": \"control: main rate\", \"actual\": 7500000, \"expected\": 7500000, \"passed\": true}, {\"check\": \"control: with dividends\", \"actual\": 2410000, \"expected\": 2350000, \"passed\": false}, {\"check\": \"control: short period\", \"actual\": 742192, \"expected\": 609041, \"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."}}