{"abstract":"Short trips show a 1.00-wide range that the contract forbids.","category":"Ride-hailing fare and surge pricing","checks":7,"contract":"Show a fare range from a point estimate in cents: low = 90% of the estimate floored to whole dollars, but never below the minimum fare; high = 110% of the estimate rounded up to whole dollars; if the range is narrower than 2.00 the high end becomes low + 2.00. Return [low, high] cents.","evaluation_group":"w2-ride-hailing-fare-surge-estimate-range","failed_approach":"Guarding against non-positive widths skips collapsed or inverted ranges created by the minimum fare clamp.","family":"w2-ride-hailing-fare-surge-estimate-range-minimum-width","id":"FA-85691","implementations":{"attempt":{"sha256":"99461bc76964aa70bb78441d860985739bec1a9cae38c6f2f112d0ad8cc47853","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(est, minimum):\n    low = max(est * 9 // 10 // 100 * 100, minimum)\n    high = -(-(est * 11) // 1000) * 100\n    if 0 < high - low < 200:\n        high = low + 200\n    return [low, high]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: minimum width', [1000, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 1000], [1000, 1200]),\n  ('second regression', [700, 800], [800, 1000]), ('normal control 1', [700, 500], [600, 800]),\n  ('normal control 2', [1111, 500], [900, 1300]), ('normal control 3', [2500, 800], [2200, 2800]),\n  ('normal control 4', [1000, 800], [900, 1100])],\n [('regression: minimum width', [1000, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 1000], [1000, 1200]),\n  ('second regression', [796, 800], [800, 1000]), ('normal control 1', [2500, 800], [2200, 2800]),\n  ('normal control 2', [1234, 800], [1100, 1400]), ('normal control 3', [1999, 500], [1700, 2200]),\n  ('normal control 4', [1000, 800], [900, 1100])],\n [('regression: minimum width', [700, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [2050, 500], [1800, 2300]),\n  ('normal control 2', [1111, 1000], [1000, 1300]), ('normal control 3', [1999, 500], [1700, 2200]),\n  ('normal control 4', [1218, 1000], [1000, 1400])],\n [('regression: minimum width', [700, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [1234, 1000], [1100, 1400]),\n  ('normal control 2', [4006, 500], [3600, 4500]), ('normal control 3', [1989, 1000], [1700, 2200]),\n  ('normal control 4', [1256, 1000], [1100, 1400])],\n [('regression: minimum width', [505, 800], [800, 1000]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [1111, 800], [900, 1300]),\n  ('normal control 2', [5958, 500], [5300, 6600]), ('normal control 3', [2050, 800], [1800, 2300]),\n  ('normal control 4', [2050, 1000], [1800, 2300])]]\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":"230ac03bbe5020d0aaa1aaa1d6fd135e9f11ee3b4258da97fe2033f808248833","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(est, minimum):\n    low = max(est * 9 // 10 // 100 * 100, minimum)\n    high = -(-(est * 11) // 1000) * 100\n    if high == low:\n        high = low + 200\n    return [low, high]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: minimum width', [1000, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 1000], [1000, 1200]),\n  ('second regression', [700, 800], [800, 1000]), ('normal control 1', [700, 500], [600, 800]),\n  ('normal control 2', [1111, 500], [900, 1300]), ('normal control 3', [2500, 800], [2200, 2800]),\n  ('normal control 4', [1000, 800], [900, 1100])],\n [('regression: minimum width', [1000, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 1000], [1000, 1200]),\n  ('second regression', [796, 800], [800, 1000]), ('normal control 1', [2500, 800], [2200, 2800]),\n  ('normal control 2', [1234, 800], [1100, 1400]), ('normal control 3', [1999, 500], [1700, 2200]),\n  ('normal control 4', [1000, 800], [900, 1100])],\n [('regression: minimum width', [700, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [2050, 500], [1800, 2300]),\n  ('normal control 2', [1111, 1000], [1000, 1300]), ('normal control 3', [1999, 500], [1700, 2200]),\n  ('normal control 4', [1218, 1000], [1000, 1400])],\n [('regression: minimum width', [700, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [1234, 1000], [1100, 1400]),\n  ('normal control 2', [4006, 500], [3600, 4500]), ('normal control 3', [1989, 1000], [1700, 2200]),\n  ('normal control 4', [1256, 1000], [1100, 1400])],\n [('regression: minimum width', [505, 800], [800, 1000]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [1111, 800], [900, 1300]),\n  ('normal control 2', [5958, 500], [5300, 6600]), ('normal control 3', [2050, 800], [1800, 2300]),\n  ('normal control 4', [2050, 1000], [1800, 2300])]]\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"},"fixed":{"sha256":"6cfbb08a0ad8910669a318f08a6d161ef0d6545ab0bf78bc712b734841e33643","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(est, minimum):\n    low = max(est * 9 // 10 // 100 * 100, minimum)\n    high = -(-(est * 11) // 1000) * 100\n    if high - low < 200:\n        high = low + 200\n    return [low, high]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: minimum width', [1000, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 1000], [1000, 1200]),\n  ('second regression', [700, 800], [800, 1000]), ('normal control 1', [700, 500], [600, 800]),\n  ('normal control 2', [1111, 500], [900, 1300]), ('normal control 3', [2500, 800], [2200, 2800]),\n  ('normal control 4', [1000, 800], [900, 1100])],\n [('regression: minimum width', [1000, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 1000], [1000, 1200]),\n  ('second regression', [796, 800], [800, 1000]), ('normal control 1', [2500, 800], [2200, 2800]),\n  ('normal control 2', [1234, 800], [1100, 1400]), ('normal control 3', [1999, 500], [1700, 2200]),\n  ('normal control 4', [1000, 800], [900, 1100])],\n [('regression: minimum width', [700, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [2050, 500], [1800, 2300]),\n  ('normal control 2', [1111, 1000], [1000, 1300]), ('normal control 3', [1999, 500], [1700, 2200]),\n  ('normal control 4', [1218, 1000], [1000, 1400])],\n [('regression: minimum width', [700, 1000], [1000, 1200]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [1234, 1000], [1100, 1400]),\n  ('normal control 2', [4006, 500], [3600, 4500]), ('normal control 3', [1989, 1000], [1700, 2200]),\n  ('normal control 4', [1256, 1000], [1100, 1400])],\n [('regression: minimum width', [505, 800], [800, 1000]),\n  ('partial repair probe: minimum width', [700, 800], [800, 1000]),\n  ('second regression', [1000, 1000], [1000, 1200]), ('normal control 1', [1111, 800], [900, 1300]),\n  ('normal control 2', [5958, 500], [5300, 6600]), ('normal control 3', [2050, 800], [1800, 2300]),\n  ('normal control 4', [2050, 1000], [1800, 2300])]]\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 toy pricing contract stipulated for this example; it does not reproduce the pricing of any real ride-hailing operator or regulator. 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-ride-hailing-fare-surge-estimate-range-minimum-width","generated_at":"2026-09-29T14:50:42.832839+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Ride-hailing prices are computed per trip at scale; ordering, unit and boundary slips become systematic over- or under-charging.","repair":"Widen the range whenever it is under 2.00.","root_cause":"The width fix only triggers when both ends are equal.","sha256":"d5053d434cd6aed0c0482c0ca1978ff95d342a828d7ba99b485f687dbf11e1d9","title":"Range narrower than two dollars shown · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":41.747,"exit_code":1,"observations":[{"actual":[1000,1200],"check":"regression: minimum width","expected":[1000,1200],"passed":true},{"actual":[1000,800],"check":"partial repair probe: minimum width","expected":[1000,1200],"passed":false},{"actual":[800,800],"check":"second regression","expected":[800,1000],"passed":false},{"actual":[600,800],"check":"normal control 1","expected":[600,800],"passed":true},{"actual":[900,1300],"check":"normal control 2","expected":[900,1300],"passed":true},{"actual":[2200,2800],"check":"normal control 3","expected":[2200,2800],"passed":true},{"actual":[900,1100],"check":"normal control 4","expected":[900,1100],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: minimum width\", \"actual\": [1000, 1200], \"expected\": [1000, 1200], \"passed\": true}, {\"check\": \"partial repair probe: minimum width\", \"actual\": [1000, 800], \"expected\": [1000, 1200], \"passed\": false}, {\"check\": \"second regression\", \"actual\": [800, 800], \"expected\": [800, 1000], \"passed\": false}, {\"check\": \"normal control 1\", \"actual\": [600, 800], \"expected\": [600, 800], \"passed\": true}, {\"check\": \"normal control 2\", \"actual\": [900, 1300], \"expected\": [900, 1300], \"passed\": true}, {\"check\": \"normal control 3\", \"actual\": [2200, 2800], \"expected\": [2200, 2800], \"passed\": true}, {\"check\": \"normal control 4\", \"actual\": [900, 1100], \"expected\": [900, 1100], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.026,"exit_code":1,"observations":[{"actual":[1000,1100],"check":"regression: minimum width","expected":[1000,1200],"passed":false},{"actual":[1000,800],"check":"partial repair probe: minimum width","expected":[1000,1200],"passed":false},{"actual":[800,1000],"check":"second regression","expected":[800,1000],"passed":true},{"actual":[600,800],"check":"normal control 1","expected":[600,800],"passed":true},{"actual":[900,1300],"check":"normal control 2","expected":[900,1300],"passed":true},{"actual":[2200,2800],"check":"normal control 3","expected":[2200,2800],"passed":true},{"actual":[900,1100],"check":"normal control 4","expected":[900,1100],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: minimum width\", \"actual\": [1000, 1100], \"expected\": [1000, 1200], \"passed\": false}, {\"check\": \"partial repair probe: minimum width\", \"actual\": [1000, 800], \"expected\": [1000, 1200], \"passed\": false}, {\"check\": \"second regression\", \"actual\": [800, 1000], \"expected\": [800, 1000], \"passed\": true}, {\"check\": \"normal control 1\", \"actual\": [600, 800], \"expected\": [600, 800], \"passed\": true}, {\"check\": \"normal control 2\", \"actual\": [900, 1300], \"expected\": [900, 1300], \"passed\": true}, {\"check\": \"normal control 3\", \"actual\": [2200, 2800], \"expected\": [2200, 2800], \"passed\": true}, {\"check\": \"normal control 4\", \"actual\": [900, 1100], \"expected\": [900, 1100], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":42.22,"exit_code":0,"observations":[{"actual":[1000,1200],"check":"regression: minimum width","expected":[1000,1200],"passed":true},{"actual":[1000,1200],"check":"partial repair probe: minimum width","expected":[1000,1200],"passed":true},{"actual":[800,1000],"check":"second regression","expected":[800,1000],"passed":true},{"actual":[600,800],"check":"normal control 1","expected":[600,800],"passed":true},{"actual":[900,1300],"check":"normal control 2","expected":[900,1300],"passed":true},{"actual":[2200,2800],"check":"normal control 3","expected":[2200,2800],"passed":true},{"actual":[900,1100],"check":"normal control 4","expected":[900,1100],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: minimum width\", \"actual\": [1000, 1200], \"expected\": [1000, 1200], \"passed\": true}, {\"check\": \"partial repair probe: minimum width\", \"actual\": [1000, 1200], \"expected\": [1000, 1200], \"passed\": true}, {\"check\": \"second regression\", \"actual\": [800, 1000], \"expected\": [800, 1000], \"passed\": true}, {\"check\": \"normal control 1\", \"actual\": [600, 800], \"expected\": [600, 800], \"passed\": true}, {\"check\": \"normal control 2\", \"actual\": [900, 1300], \"expected\": [900, 1300], \"passed\": true}, {\"check\": \"normal control 3\", \"actual\": [2200, 2800], \"expected\": [2200, 2800], \"passed\": true}, {\"check\": \"normal control 4\", \"actual\": [900, 1100], \"expected\": [900, 1100], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}