{"abstract":"One-cycle schedule extrapolates beyond its endpoints.","category":"Learning rate schedules","checks":7,"contract":"Rise linearly from low to peak over rise_steps, then fall linearly to low by total.","contract_signature":"step, low, peak, rise_steps, total","evaluation_group":"lr-schedule-one-cycle","failed_approach":"Clamping only the upper endpoint leaves negative steps below the configured low rate.","family":"w3-learning-rate-schedules-one-cycle","id":"FA-99131","implementations":{"attempt":{"sha256":"0ce63601487ae5888537ac102ce95f929a51af43e87dc142eb5833c8a7bac2cc","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(step, low, peak, rise_steps, total):\n    step=min(total,step)\n    if step<=rise_steps: return low+(peak-low)*step/rise_steps\n    return peak-(peak-low)*(step-rise_steps)/(total-rise_steps)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('start',solve(0,2,10,2,6),2); check('rise',solve(1,2,10,2,6),6); check('peak',solve(2,2,10,2,6),10); check('fall',solve(4,2,10,2,6),6); check('end',solve(6,2,10,2,6),2); check('after',solve(8,2,10,2,6),2); check('before',solve(-1,2,10,2,6),2)\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":"8a597af6b1659139f88305ab9fab1921f9f2c10c2eea3ad39dea76c10cf8797f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(step, low, peak, rise_steps, total):\n    if step<=rise_steps: return low+(peak-low)*step/rise_steps\n    return peak-(peak-low)*(step-rise_steps)/(total-rise_steps)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('start',solve(0,2,10,2,6),2); check('rise',solve(1,2,10,2,6),6); check('peak',solve(2,2,10,2,6),10); check('fall',solve(4,2,10,2,6),6); check('end',solve(6,2,10,2,6),2); check('after',solve(8,2,10,2,6),2); check('before',solve(-1,2,10,2,6),2)\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":"These are toy scalar contracts with integer steps and finite parameters; they do not model framework defaults or optimizer state. 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":"w3-learning-rate-schedules-one-cycle","generated_at":"2026-09-30T16:48:20.798992+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic scalar schedule makes step-to-rate mapping explicit for a small training loop.","root_cause":"The piecewise ramp uses raw step values with no bounds at either end of the cycle.","sha256":"5f9ab18a7a4b0bf3a895047356690702ef2b4b623656e03f5e3443874ef15765","title":"One-cycle schedule extrapolates beyond its endpoints · case 01","variant":1,"variant_policy":"The same explicitly authored fixtures repeat across all five numbered records; runtime N is unused. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":25.358,"exit_code":1,"observations":[{"actual":2.0,"check":"start","expected":2,"passed":true},{"actual":6.0,"check":"rise","expected":6,"passed":true},{"actual":10.0,"check":"peak","expected":10,"passed":true},{"actual":6.0,"check":"fall","expected":6,"passed":true},{"actual":2.0,"check":"end","expected":2,"passed":true},{"actual":2.0,"check":"after","expected":2,"passed":true},{"actual":-2.0,"check":"before","expected":2,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"start\", \"actual\": 2.0, \"expected\": 2, \"passed\": true}, {\"check\": \"rise\", \"actual\": 6.0, \"expected\": 6, \"passed\": true}, {\"check\": \"peak\", \"actual\": 10.0, \"expected\": 10, \"passed\": true}, {\"check\": \"fall\", \"actual\": 6.0, \"expected\": 6, \"passed\": true}, {\"check\": \"end\", \"actual\": 2.0, \"expected\": 2, \"passed\": true}, {\"check\": \"after\", \"actual\": 2.0, \"expected\": 2, \"passed\": true}, {\"check\": \"before\", \"actual\": -2.0, \"expected\": 2, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":28.65,"exit_code":1,"observations":[{"actual":2.0,"check":"start","expected":2,"passed":true},{"actual":6.0,"check":"rise","expected":6,"passed":true},{"actual":10.0,"check":"peak","expected":10,"passed":true},{"actual":6.0,"check":"fall","expected":6,"passed":true},{"actual":2.0,"check":"end","expected":2,"passed":true},{"actual":-2.0,"check":"after","expected":2,"passed":false},{"actual":-2.0,"check":"before","expected":2,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"start\", \"actual\": 2.0, \"expected\": 2, \"passed\": true}, {\"check\": \"rise\", \"actual\": 6.0, \"expected\": 6, \"passed\": true}, {\"check\": \"peak\", \"actual\": 10.0, \"expected\": 10, \"passed\": true}, {\"check\": \"fall\", \"actual\": 6.0, \"expected\": 6, \"passed\": true}, {\"check\": \"end\", \"actual\": 2.0, \"expected\": 2, \"passed\": true}, {\"check\": \"after\", \"actual\": -2.0, \"expected\": 2, \"passed\": false}, {\"check\": \"before\", \"actual\": -2.0, \"expected\": 2, \"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."}}