{"abstract":"An interval end label selects the next tariff period.","category":"Power metering accounting","checks":6,"contract":"Rows [end, energy] represent one-slot intervals (end-1,end]. A tariff changes at boundary b: intervals starting below b cost low, others high. Return integer charge; all labels and boundaries are integer slots.","evaluation_group":"model-d9ba806d269f413e","failed_approach":"Treating only the boundary-ending interval as low assigns every earlier interval the high rate.","family":"z-power_metering-end-labelled-tariff","id":"FA-12256","implementations":{"attempt":{"sha256":"d67220dc3895719aa4a7455cdf3ee39d143faab2e691ce0edfbcdf3015f019bf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(rows, boundary, low, high):\n    return sum(e*(low if end == boundary else high) for end,e in rows)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('ends at transition', solve([[10,N]],10,2,7),2*N)\ncheck('starts at transition', solve([[11,N]],10,2,7),7*N)\ncheck('strictly earlier', solve([[8,N]],10,2,7),2*N)\ncheck('mixed intervals', solve([[9,N],[10,N],[11,N]],10,2,7),11*N)\ncheck('empty', solve([],10,2,7),0)\ncheck('zero priced period', solve([[10,N]],10,0,7),0)\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":"89e4806ff9d1ba6eda3413c4cdab6ee3efa11b6de306a08ad2d3bedcb923ea6f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(rows, boundary, low, high):\n    return sum(e*(low if end < boundary else high) for end,e in rows)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('ends at transition', solve([[10,N]],10,2,7),2*N)\ncheck('starts at transition', solve([[11,N]],10,2,7),7*N)\ncheck('strictly earlier', solve([[8,N]],10,2,7),2*N)\ncheck('mixed intervals', solve([[9,N],[10,N],[11,N]],10,2,7),11*N)\ncheck('empty', solve([],10,2,7),0)\ncheck('zero priced period', solve([[10,N]],10,0,7),0)\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":"567a82f0d131b5306782a0b65fd3f5f9b792baac05a000cf83ad90705ffe77f9","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(rows, boundary, low, high):\n    return sum(e*(low if end-1 < boundary else high) for end,e in rows)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('ends at transition', solve([[10,N]],10,2,7),2*N)\ncheck('starts at transition', solve([[11,N]],10,2,7),7*N)\ncheck('strictly earlier', solve([[8,N]],10,2,7),2*N)\ncheck('mixed intervals', solve([[9,N],[10,N],[11,N]],10,2,7),11*N)\ncheck('empty', solve([],10,2,7),0)\ncheck('zero priced period', solve([[10,N]],10,0,7),0)\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":"Simplified integer-energy accounting model; no hardware protocol, legal tariff, measurement uncertainty, or live grid behavior is represented. 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":"z-power_metering-end-labelled-tariff","generated_at":"2026-09-29T14:38:55.321996+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Meter settlement depends on explicit register and tariff policies; this controlled model makes that policy observable.","repair":"Resolve the tariff using the interval start slot.","root_cause":"The interval end timestamp is used as the tariff effective timestamp.","sha256":"57cc3a7397e2d2639211dcc0efc6927525c9e6f2d6a72c448e685081823c775b","title":"An interval end label selects the next tariff period · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.086,"exit_code":1,"observations":[{"actual":2,"check":"ends at transition","expected":2,"passed":true},{"actual":7,"check":"starts at transition","expected":7,"passed":true},{"actual":7,"check":"strictly earlier","expected":2,"passed":false},{"actual":16,"check":"mixed intervals","expected":11,"passed":false},{"actual":0,"check":"empty","expected":0,"passed":true},{"actual":0,"check":"zero priced period","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ends at transition\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"starts at transition\", \"actual\": 7, \"expected\": 7, \"passed\": true}, {\"check\": \"strictly earlier\", \"actual\": 7, \"expected\": 2, \"passed\": false}, {\"check\": \"mixed intervals\", \"actual\": 16, \"expected\": 11, \"passed\": false}, {\"check\": \"empty\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"zero priced period\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.816,"exit_code":1,"observations":[{"actual":7,"check":"ends at transition","expected":2,"passed":false},{"actual":7,"check":"starts at transition","expected":7,"passed":true},{"actual":2,"check":"strictly earlier","expected":2,"passed":true},{"actual":16,"check":"mixed intervals","expected":11,"passed":false},{"actual":0,"check":"empty","expected":0,"passed":true},{"actual":7,"check":"zero priced period","expected":0,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ends at transition\", \"actual\": 7, \"expected\": 2, \"passed\": false}, {\"check\": \"starts at transition\", \"actual\": 7, \"expected\": 7, \"passed\": true}, {\"check\": \"strictly earlier\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"mixed intervals\", \"actual\": 16, \"expected\": 11, \"passed\": false}, {\"check\": \"empty\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"zero priced period\", \"actual\": 7, \"expected\": 0, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.609,"exit_code":0,"observations":[{"actual":2,"check":"ends at transition","expected":2,"passed":true},{"actual":7,"check":"starts at transition","expected":7,"passed":true},{"actual":2,"check":"strictly earlier","expected":2,"passed":true},{"actual":11,"check":"mixed intervals","expected":11,"passed":true},{"actual":0,"check":"empty","expected":0,"passed":true},{"actual":0,"check":"zero priced period","expected":0,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ends at transition\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"starts at transition\", \"actual\": 7, \"expected\": 7, \"passed\": true}, {\"check\": \"strictly earlier\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"mixed intervals\", \"actual\": 11, \"expected\": 11, \"passed\": true}, {\"check\": \"empty\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"zero priced period\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}