{"abstract":"Slips whose remainder is 0 or 1 get verifying digit 0, which is reserved.","category":"Check-digit algorithms","checks":8,"contract":"Bank-slip style mod-11 verifying digit: nonempty ASCII digits (else None); weights 2,3,...,9 cycle from the rightmost digit; r = 11 - sum mod 11; results 10 and 11 are replaced by 1.","contract_signature":"s","evaluation_group":"w2-check_digit_algorithms-boleto-mod11","failed_approach":"Using r % 10 sends 10 to 0 and 11 to 1, fixing only one case.","family":"w2-check_digit_algorithms-boleto-mod11-reserved-results","id":"FA-72816","implementations":{"attempt":{"sha256":"0dce811cd98225d3de6b48195686391dc8e42c67e9bf7204c28912cd3ebdb6b0","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(s):\n    if not s or not s.isascii() or not s.isdigit():\n        return None\n    total = 0\n    for i, ch in enumerate(reversed(s)):\n        total += int(ch) * (2 + i % 8)\n    r = 11 - total % 11\n    return r % 10\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['regression [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['regression [\"067817050276532142767980812420339104011\"]', ['067817050276532142767980812420339104011'], 1], ['partial-repair [\"54\"]', ['54'], 1], ['control [\"81787654\"]', ['81787654'], 5], ['control [\"4216186312776190006424731500839778176090\"]', ['4216186312776190006424731500839778176090'], 9], ['control [\"0154413110088423\"]', ['0154413110088423'], 4], ['control [\"2265387292381697\"]', ['2265387292381697'], 4], ['control [\"157141363073674774805\"]', ['157141363073674774805'], 2]], [['regression [\"883588303\"]', ['883588303'], 1], ['regression [\"54\"]', ['54'], 1], ['partial-repair [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['control [\"32390980174642183951992567\"]', ['32390980174642183951992567'], 6], ['control [\"31028572572652095\"]', ['31028572572652095'], 8], ['control [\"1013803677685407598527336083735651\"]', ['1013803677685407598527336083735651'], 1], ['control [\"541856920526325212396079880824962283\"]', ['541856920526325212396079880824962283'], 9], ['control [\"90636853841379\"]', ['90636853841379'], 8]], [['regression [\"27981996326643088365414819731338534\"]', ['27981996326643088365414819731338534'], 1], ['regression [\"0\"]', ['0'], 1], ['partial-repair [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['partial-repair [\"54\"]', ['54'], 1], ['control [\"815243122823727656729727617889\"]', ['815243122823727656729727617889'], 4], ['control [\"866534787261435696309320\"]', ['866534787261435696309320'], 1], ['control [\"59608070035358359099925603574938148494060\"]', ['59608070035358359099925603574938148494060'], 2], ['control [\"2567041842604142121509116255\"]', ['2567041842604142121509116255'], 9]], [['regression [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['regression [\"067817050276532142767980812420339104011\"]', ['067817050276532142767980812420339104011'], 1], ['partial-repair [\"54\"]', ['54'], 1], ['control [\"666316543903176040\"]', ['666316543903176040'], 7], ['control [\"221858430508251943268773964844902173\"]', ['221858430508251943268773964844902173'], 8], ['control [\"26064317433322755425\"]', ['26064317433322755425'], 2], ['control [\"635756761654188\"]', ['635756761654188'], 1], ['control [\"1\"]', ['1'], 9]], [['regression [\"883588303\"]', ['883588303'], 1], ['regression [\"54\"]', ['54'], 1], ['partial-repair [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['control [\"\"]', [''], None], ['control [\"12x\"]', ['12x'], None], ['control [\"9999999999999999999999999999999999999999999\"]', ['9999999999999999999999999999999999999999999'], 7], ['control [\"81787654\"]', ['81787654'], 5], ['control [\"4216186312776190006424731500839778176090\"]', ['4216186312776190006424731500839778176090'], 9]]]\nfor label, args, expected in fixtures[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":"5a1f9f7bfe22f491a6ffb5c74a6545b32394fd01c4806c9684e54f28c3dc1350","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(s):\n    if not s or not s.isascii() or not s.isdigit():\n        return None\n    total = 0\n    for i, ch in enumerate(reversed(s)):\n        total += int(ch) * (2 + i % 8)\n    r = 11 - total % 11\n    return 0 if r in (10, 11) else r\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['regression [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['regression [\"067817050276532142767980812420339104011\"]', ['067817050276532142767980812420339104011'], 1], ['partial-repair [\"54\"]', ['54'], 1], ['control [\"81787654\"]', ['81787654'], 5], ['control [\"4216186312776190006424731500839778176090\"]', ['4216186312776190006424731500839778176090'], 9], ['control [\"0154413110088423\"]', ['0154413110088423'], 4], ['control [\"2265387292381697\"]', ['2265387292381697'], 4], ['control [\"157141363073674774805\"]', ['157141363073674774805'], 2]], [['regression [\"883588303\"]', ['883588303'], 1], ['regression [\"54\"]', ['54'], 1], ['partial-repair [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['control [\"32390980174642183951992567\"]', ['32390980174642183951992567'], 6], ['control [\"31028572572652095\"]', ['31028572572652095'], 8], ['control [\"1013803677685407598527336083735651\"]', ['1013803677685407598527336083735651'], 1], ['control [\"541856920526325212396079880824962283\"]', ['541856920526325212396079880824962283'], 9], ['control [\"90636853841379\"]', ['90636853841379'], 8]], [['regression [\"27981996326643088365414819731338534\"]', ['27981996326643088365414819731338534'], 1], ['regression [\"0\"]', ['0'], 1], ['partial-repair [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['partial-repair [\"54\"]', ['54'], 1], ['control [\"815243122823727656729727617889\"]', ['815243122823727656729727617889'], 4], ['control [\"866534787261435696309320\"]', ['866534787261435696309320'], 1], ['control [\"59608070035358359099925603574938148494060\"]', ['59608070035358359099925603574938148494060'], 2], ['control [\"2567041842604142121509116255\"]', ['2567041842604142121509116255'], 9]], [['regression [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['regression [\"067817050276532142767980812420339104011\"]', ['067817050276532142767980812420339104011'], 1], ['partial-repair [\"54\"]', ['54'], 1], ['control [\"666316543903176040\"]', ['666316543903176040'], 7], ['control [\"221858430508251943268773964844902173\"]', ['221858430508251943268773964844902173'], 8], ['control [\"26064317433322755425\"]', ['26064317433322755425'], 2], ['control [\"635756761654188\"]', ['635756761654188'], 1], ['control [\"1\"]', ['1'], 9]], [['regression [\"883588303\"]', ['883588303'], 1], ['regression [\"54\"]', ['54'], 1], ['partial-repair [\"19275955179485910051680234501004684803\"]', ['19275955179485910051680234501004684803'], 1], ['control [\"\"]', [''], None], ['control [\"12x\"]', ['12x'], None], ['control [\"9999999999999999999999999999999999999999999\"]', ['9999999999999999999999999999999999999999999'], 7], ['control [\"81787654\"]', ['81787654'], 5], ['control [\"4216186312776190006424731500839778176090\"]', ['4216186312776190006424731500839778176090'], 9]]]\nfor label, args, expected in fixtures[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 of the named scheme under the stated contract; not a certified validator. 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-check_digit_algorithms-boleto-mod11-reserved-results","generated_at":"2026-09-29T14:48:41.807199+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Payment slip barcodes carry a general verifying digit that banks recompute on capture.","root_cause":"The substitution for 10 and 11 uses 0 instead of 1.","sha256":"f11297b6f62acd41cae3f51c2513a07f3221d486069c211663abdbea09ce7ca2","title":"Bank-slip mod 11 maps 10 and 11 to zero · 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":39.456,"exit_code":1,"observations":[{"actual":0,"check":"regression [\"19275955179485910051680234501004684803\"]","expected":1,"passed":false},{"actual":1,"check":"regression [\"067817050276532142767980812420339104011\"]","expected":1,"passed":true},{"actual":0,"check":"partial-repair [\"54\"]","expected":1,"passed":false},{"actual":5,"check":"control [\"81787654\"]","expected":5,"passed":true},{"actual":9,"check":"control [\"4216186312776190006424731500839778176090\"]","expected":9,"passed":true},{"actual":4,"check":"control [\"0154413110088423\"]","expected":4,"passed":true},{"actual":4,"check":"control [\"2265387292381697\"]","expected":4,"passed":true},{"actual":2,"check":"control [\"157141363073674774805\"]","expected":2,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression [\\\"19275955179485910051680234501004684803\\\"]\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"regression [\\\"067817050276532142767980812420339104011\\\"]\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"partial-repair [\\\"54\\\"]\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"control [\\\"81787654\\\"]\", \"actual\": 5, \"expected\": 5, \"passed\": true}, {\"check\": \"control [\\\"4216186312776190006424731500839778176090\\\"]\", \"actual\": 9, \"expected\": 9, \"passed\": true}, {\"check\": \"control [\\\"0154413110088423\\\"]\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"control [\\\"2265387292381697\\\"]\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"control [\\\"157141363073674774805\\\"]\", \"actual\": 2, \"expected\": 2, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.731,"exit_code":1,"observations":[{"actual":0,"check":"regression [\"19275955179485910051680234501004684803\"]","expected":1,"passed":false},{"actual":0,"check":"regression [\"067817050276532142767980812420339104011\"]","expected":1,"passed":false},{"actual":0,"check":"partial-repair [\"54\"]","expected":1,"passed":false},{"actual":5,"check":"control [\"81787654\"]","expected":5,"passed":true},{"actual":9,"check":"control [\"4216186312776190006424731500839778176090\"]","expected":9,"passed":true},{"actual":4,"check":"control [\"0154413110088423\"]","expected":4,"passed":true},{"actual":4,"check":"control [\"2265387292381697\"]","expected":4,"passed":true},{"actual":2,"check":"control [\"157141363073674774805\"]","expected":2,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression [\\\"19275955179485910051680234501004684803\\\"]\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"regression [\\\"067817050276532142767980812420339104011\\\"]\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"partial-repair [\\\"54\\\"]\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"control [\\\"81787654\\\"]\", \"actual\": 5, \"expected\": 5, \"passed\": true}, {\"check\": \"control [\\\"4216186312776190006424731500839778176090\\\"]\", \"actual\": 9, \"expected\": 9, \"passed\": true}, {\"check\": \"control [\\\"0154413110088423\\\"]\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"control [\\\"2265387292381697\\\"]\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"control [\\\"157141363073674774805\\\"]\", \"actual\": 2, \"expected\": 2, \"passed\": true}], \"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."}}