{"abstract":"A quiet zone with no drivers and no riders publishes 3.0x.","category":"Ride-hailing fare and surge pricing","checks":7,"contract":"Each interval gives [open requests, idle drivers]. The raw multiplier (tenths) is 30 when the exact ratio requests/drivers >= 3, 20 when >= 2, 15 when >= 1.5, 12 when >= 1.2, else 10; with zero drivers it is 30 if any request is open, else 10. The published multiplier rises immediately to the raw value but falls by at most 2 tenths per interval, starting from prev. Return the published multiplier per interval.","contract_signature":"obs, prev","evaluation_group":"w2-ride-hailing-fare-surge-surge-hysteresis","failed_approach":"Requiring two requests ignores a single stranded rider.","family":"w2-ride-hailing-fare-surge-surge-hysteresis-empty-market","id":"FA-85366","implementations":{"attempt":{"sha256":"d3eca453f58482cf9e52cf5862cc0e756ee7873ae4b04edfeb19af9f1f1abe3b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(obs, prev):\n    tiers = [(30, 30), (20, 20), (15, 15), (12, 12)]\n    cur = prev\n    out = []\n    for req, drv in obs:\n        raw = 10\n        if drv == 0:\n            raw = 30 if req > 1 else 10\n        else:\n            for th, mult in tiers:\n                if req * 10 >= th * drv:\n                    raw = mult\n                    break\n        cur = raw if raw >= cur else max(raw, cur - 2)\n        out.append(cur)\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: empty market', [[[39, 20], [16, 7], [-1, 0], [-1, 0]], 15], [15, 20, 18, 16]),\n  ('partial repair probe: empty market', [[[60, 20], [4, 5], [1, 0], [5, 5]], 15], [30, 28, 30, 28]),\n  ('second regression', [[[32, 0], [-1, 0]], 30], [30, 28]),\n  ('normal control 1', [[[0, 10], [15, 10]], 12], [10, 15]),\n  ('normal control 2', [[[15, 5], [12, 7], [18, 0], [6, 7]], 15], [30, 28, 30, 28]),\n  ('normal control 3', [[[5, 10], [3, 7], [33, 7], [7, 7]], 20], [18, 16, 30, 28]),\n  ('normal control 4', [[[27, 10], [37, 0], [7, 5], [23, 10], [10, 5], [15, 5]], 15],\n   [20, 30, 28, 26, 24, 30])],\n [('regression: empty market', [[[-1, 0], [5, 10], [12, 10]], 10], [10, 10, 12]),\n  ('partial repair probe: empty market', [[[1, 0], [-1, 0], [10, 7]], 15], [30, 28, 26]),\n  ('second regression', [[[20, 10], [7, 7], [0, 0], [22, 20]], 15], [20, 18, 16, 14]),\n  ('normal control 1', [[[11, 10], [23, 5], [4, 5], [12, 10]], 12], [10, 30, 28, 26]),\n  ('normal control 2', [[[6, 5], [30, 10], [9, 10], [14, 5]], 30], [28, 30, 28, 26]),\n  ('normal control 3', [[[18, 5], [10, 10], [5, 10]], 12], [30, 28, 26]),\n  ('normal control 4', [[[13, 7], [17, 5], [4, 10], [29, 10], [10, 10], [19, 10]], 20],\n   [18, 30, 28, 26, 24, 22])],\n [('regression: empty market', [[[5, 10], [10, 20], [36, 10], [-1, 0]], 20], [18, 16, 30, 28]),\n  ('partial repair probe: empty market', [[[7, 7], [7, 7], [1, 0]], 30], [28, 26, 30]),\n  ('second regression', [[[1, 20], [36, 5], [0, 0], [10, 20], [0, 0]], 15], [13, 30, 28, 26, 24]),\n  ('normal control 1', [[[30, 10], [6, 7], [10, 7], [31, 7]], 10], [30, 28, 26, 30]),\n  ('normal control 2', [[[21, 20], [10, 10]], 10], [10, 10]),\n  ('normal control 3', [[[20, 5], [20, 7], [19, 20], [7, 7], [5, 10], [5, 10]], 15],\n   [30, 28, 26, 24, 22, 20]),\n  ('normal control 4', [[[4, 10], [20, 20], [4, 5]], 10], [10, 10, 10])],\n [('regression: empty market', [[[35, 5], [40, 20], [19, 10], [13, 7], [-1, 0], [14, 7]], 30],\n   [30, 28, 26, 24, 22, 20]),\n  ('partial repair probe: empty market', [[[11, 10], [18, 5], [17, 10], [5, 5], [1, 0]], 10],\n   [10, 30, 28, 26, 30]),\n  ('second regression', [[[36, 7], [6, 7], [-1, 0], [10, 20]], 20], [30, 28, 26, 24]),\n  ('normal control 1', [[[6, 5], [17, 10]], 15], [13, 15]),\n  ('normal control 2', [[[20, 20], [12, 7], [15, 5], [15, 5], [40, 20]], 10], [10, 15, 30, 30, 28]),\n  ('normal control 3', [[[7, 20], [10, 20]], 20], [18, 16]),\n  ('normal control 4', [[[38, 20], [20, 20], [20, 10]], 12], [15, 13, 20])],\n [('regression: empty market', [[[0, 0], [12, 5], [11, 7]], 15], [13, 20, 18]),\n  ('partial repair probe: empty market', [[[25, 5], [0, 0], [1, 0]], 10], [30, 28, 30]),\n  ('second regression', [[[19, 10], [7, 0], [10, 10], [-1, 0], [21, 20], [-1, 0]], 30],\n   [28, 30, 28, 26, 24, 22]),\n  ('normal control 1', [[[18, 10], [10, 7], [16, 5]], 12], [15, 13, 30]),\n  ('normal control 2', [[[14, 7], [20, 10], [29, 10], [29, 5], [27, 10], [20, 20]], 15],\n   [20, 20, 20, 30, 28, 26]),\n  ('normal control 3', [[[4, 10], [9, 5]], 12], [10, 15]),\n  ('normal control 4', [[[29, 7], [6, 5], [13, 7], [30, 20], [27, 10], [10, 10]], 10],\n   [30, 28, 26, 24, 22, 20])]]\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":"edbfbda807f91e41f0c7ac452412c880682bd90ff81ceb4ad0e6eae58b0eeee8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(obs, prev):\n    tiers = [(30, 30), (20, 20), (15, 15), (12, 12)]\n    cur = prev\n    out = []\n    for req, drv in obs:\n        raw = 10\n        if drv == 0:\n            raw = 30\n        else:\n            for th, mult in tiers:\n                if req * 10 >= th * drv:\n                    raw = mult\n                    break\n        cur = raw if raw >= cur else max(raw, cur - 2)\n        out.append(cur)\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: empty market', [[[39, 20], [16, 7], [-1, 0], [-1, 0]], 15], [15, 20, 18, 16]),\n  ('partial repair probe: empty market', [[[60, 20], [4, 5], [1, 0], [5, 5]], 15], [30, 28, 30, 28]),\n  ('second regression', [[[32, 0], [-1, 0]], 30], [30, 28]),\n  ('normal control 1', [[[0, 10], [15, 10]], 12], [10, 15]),\n  ('normal control 2', [[[15, 5], [12, 7], [18, 0], [6, 7]], 15], [30, 28, 30, 28]),\n  ('normal control 3', [[[5, 10], [3, 7], [33, 7], [7, 7]], 20], [18, 16, 30, 28]),\n  ('normal control 4', [[[27, 10], [37, 0], [7, 5], [23, 10], [10, 5], [15, 5]], 15],\n   [20, 30, 28, 26, 24, 30])],\n [('regression: empty market', [[[-1, 0], [5, 10], [12, 10]], 10], [10, 10, 12]),\n  ('partial repair probe: empty market', [[[1, 0], [-1, 0], [10, 7]], 15], [30, 28, 26]),\n  ('second regression', [[[20, 10], [7, 7], [0, 0], [22, 20]], 15], [20, 18, 16, 14]),\n  ('normal control 1', [[[11, 10], [23, 5], [4, 5], [12, 10]], 12], [10, 30, 28, 26]),\n  ('normal control 2', [[[6, 5], [30, 10], [9, 10], [14, 5]], 30], [28, 30, 28, 26]),\n  ('normal control 3', [[[18, 5], [10, 10], [5, 10]], 12], [30, 28, 26]),\n  ('normal control 4', [[[13, 7], [17, 5], [4, 10], [29, 10], [10, 10], [19, 10]], 20],\n   [18, 30, 28, 26, 24, 22])],\n [('regression: empty market', [[[5, 10], [10, 20], [36, 10], [-1, 0]], 20], [18, 16, 30, 28]),\n  ('partial repair probe: empty market', [[[7, 7], [7, 7], [1, 0]], 30], [28, 26, 30]),\n  ('second regression', [[[1, 20], [36, 5], [0, 0], [10, 20], [0, 0]], 15], [13, 30, 28, 26, 24]),\n  ('normal control 1', [[[30, 10], [6, 7], [10, 7], [31, 7]], 10], [30, 28, 26, 30]),\n  ('normal control 2', [[[21, 20], [10, 10]], 10], [10, 10]),\n  ('normal control 3', [[[20, 5], [20, 7], [19, 20], [7, 7], [5, 10], [5, 10]], 15],\n   [30, 28, 26, 24, 22, 20]),\n  ('normal control 4', [[[4, 10], [20, 20], [4, 5]], 10], [10, 10, 10])],\n [('regression: empty market', [[[35, 5], [40, 20], [19, 10], [13, 7], [-1, 0], [14, 7]], 30],\n   [30, 28, 26, 24, 22, 20]),\n  ('partial repair probe: empty market', [[[11, 10], [18, 5], [17, 10], [5, 5], [1, 0]], 10],\n   [10, 30, 28, 26, 30]),\n  ('second regression', [[[36, 7], [6, 7], [-1, 0], [10, 20]], 20], [30, 28, 26, 24]),\n  ('normal control 1', [[[6, 5], [17, 10]], 15], [13, 15]),\n  ('normal control 2', [[[20, 20], [12, 7], [15, 5], [15, 5], [40, 20]], 10], [10, 15, 30, 30, 28]),\n  ('normal control 3', [[[7, 20], [10, 20]], 20], [18, 16]),\n  ('normal control 4', [[[38, 20], [20, 20], [20, 10]], 12], [15, 13, 20])],\n [('regression: empty market', [[[0, 0], [12, 5], [11, 7]], 15], [13, 20, 18]),\n  ('partial repair probe: empty market', [[[25, 5], [0, 0], [1, 0]], 10], [30, 28, 30]),\n  ('second regression', [[[19, 10], [7, 0], [10, 10], [-1, 0], [21, 20], [-1, 0]], 30],\n   [28, 30, 28, 26, 24, 22]),\n  ('normal control 1', [[[18, 10], [10, 7], [16, 5]], 12], [15, 13, 30]),\n  ('normal control 2', [[[14, 7], [20, 10], [29, 10], [29, 5], [27, 10], [20, 20]], 15],\n   [20, 20, 20, 30, 28, 26]),\n  ('normal control 3', [[[4, 10], [9, 5]], 12], [10, 15]),\n  ('normal control 4', [[[29, 7], [6, 5], [13, 7], [30, 20], [27, 10], [10, 10]], 10],\n   [30, 28, 26, 24, 22, 20])]]\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-surge-hysteresis-empty-market","generated_at":"2026-09-29T14:50:39.723187+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.","root_cause":"Any zone with zero idle drivers gets the maximum multiplier.","sha256":"2c73d19bf756e72de912f69e24fea59861801d36280f73e4dee9973758eb0fc2","title":"Zero drivers and zero requests treated as maximum surge · 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":42.613,"exit_code":1,"observations":[{"actual":[15,20,18,16],"check":"regression: empty market","expected":[15,20,18,16],"passed":true},{"actual":[30,28,26,24],"check":"partial repair probe: empty market","expected":[30,28,30,28],"passed":false},{"actual":[30,28],"check":"second regression","expected":[30,28],"passed":true},{"actual":[10,15],"check":"normal control 1","expected":[10,15],"passed":true},{"actual":[30,28,30,28],"check":"normal control 2","expected":[30,28,30,28],"passed":true},{"actual":[18,16,30,28],"check":"normal control 3","expected":[18,16,30,28],"passed":true},{"actual":[20,30,28,26,24,30],"check":"normal control 4","expected":[20,30,28,26,24,30],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: empty market\", \"actual\": [15, 20, 18, 16], \"expected\": [15, 20, 18, 16], \"passed\": true}, {\"check\": \"partial repair probe: empty market\", \"actual\": [30, 28, 26, 24], \"expected\": [30, 28, 30, 28], \"passed\": false}, {\"check\": \"second regression\", \"actual\": [30, 28], \"expected\": [30, 28], \"passed\": true}, {\"check\": \"normal control 1\", \"actual\": [10, 15], \"expected\": [10, 15], \"passed\": true}, {\"check\": \"normal control 2\", \"actual\": [30, 28, 30, 28], \"expected\": [30, 28, 30, 28], \"passed\": true}, {\"check\": \"normal control 3\", \"actual\": [18, 16, 30, 28], \"expected\": [18, 16, 30, 28], \"passed\": true}, {\"check\": \"normal control 4\", \"actual\": [20, 30, 28, 26, 24, 30], \"expected\": [20, 30, 28, 26, 24, 30], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.2,"exit_code":1,"observations":[{"actual":[15,20,30,30],"check":"regression: empty market","expected":[15,20,18,16],"passed":false},{"actual":[30,28,30,28],"check":"partial repair probe: empty market","expected":[30,28,30,28],"passed":true},{"actual":[30,30],"check":"second regression","expected":[30,28],"passed":false},{"actual":[10,15],"check":"normal control 1","expected":[10,15],"passed":true},{"actual":[30,28,30,28],"check":"normal control 2","expected":[30,28,30,28],"passed":true},{"actual":[18,16,30,28],"check":"normal control 3","expected":[18,16,30,28],"passed":true},{"actual":[20,30,28,26,24,30],"check":"normal control 4","expected":[20,30,28,26,24,30],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: empty market\", \"actual\": [15, 20, 30, 30], \"expected\": [15, 20, 18, 16], \"passed\": false}, {\"check\": \"partial repair probe: empty market\", \"actual\": [30, 28, 30, 28], \"expected\": [30, 28, 30, 28], \"passed\": true}, {\"check\": \"second regression\", \"actual\": [30, 30], \"expected\": [30, 28], \"passed\": false}, {\"check\": \"normal control 1\", \"actual\": [10, 15], \"expected\": [10, 15], \"passed\": true}, {\"check\": \"normal control 2\", \"actual\": [30, 28, 30, 28], \"expected\": [30, 28, 30, 28], \"passed\": true}, {\"check\": \"normal control 3\", \"actual\": [18, 16, 30, 28], \"expected\": [18, 16, 30, 28], \"passed\": true}, {\"check\": \"normal control 4\", \"actual\": [20, 30, 28, 26, 24, 30], \"expected\": [20, 30, 28, 26, 24, 30], \"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."}}