{"abstract":"The pan law doubles total amplitude by omitting normalization.","category":"Audio channel mixing","checks":4,"contract":"Pan mono into stereo using a linear constant-sum law with pan in [-1,1], negative left and positive right; this is not an equal-power law.","evaluation_group":"xaud-pan-linear-complement","failed_approach":"Swapping the complement factors reverses pan direction.","family":"xaud-pan-linear-complement","id":"FA-10931","implementations":{"attempt":{"sha256":"1b2f419c81564d89301696fecef65bf1cb355eddad3b56f1a05e9ffef8aab61c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, pan):\n    return [[x*(1+pan)/2,x*(1-pan)/2] for x in samples]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1], 0)),[[0.5, 0.5]])\ncheck('fixture 2',solve(*([1], -1)),[[1, 0]])\ncheck('fixture 3',solve(*([1], 1)),[[0, 1]])\ncheck('fixture 4',solve(*([], 0.5)),[])\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":"6c237396f91a18525b7ee9b83b14e152f0803cf470d89327882d95b31cad7f6d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, pan):\n    return [[x*(1-pan),x*(1+pan)] for x in samples]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1], 0)),[[0.5, 0.5]])\ncheck('fixture 2',solve(*([1], -1)),[[1, 0]])\ncheck('fixture 3',solve(*([1], 1)),[[0, 1]])\ncheck('fixture 4',solve(*([], 0.5)),[])\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":"2b94835c03489dc15352069c9b596c1a7fd20bcf54ab29df045a4f64d55c2575","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, pan):\n    return [[x*(1-pan)/2,x*(1+pan)/2] for x in samples]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1], 0)),[[0.5, 0.5]])\ncheck('fixture 2',solve(*([1], -1)),[[1, 0]])\ncheck('fixture 3',solve(*([1], 1)),[[0, 1]])\ncheck('fixture 4',solve(*([], 0.5)),[])\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":" 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":"xaud-pan-linear-complement","generated_at":"2026-09-29T14:38:43.512015+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.","repair":"Apply the explicit PCM/playback contract: Pan mono into stereo using a linear constant-sum law with pan in [-1,1], negative left and positive right; this is not an equal-power law.","root_cause":"The pan law doubles total amplitude by omitting normalization.","sha256":"7f77ef54cf39d2252f808429daf23c5b6479341dea030acbcd5d979c3a36bca8","title":"Pan linear complement · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":37.947,"exit_code":1,"observations":[{"actual":[[0.5,0.5]],"check":"fixture 1","expected":[[0.5,0.5]],"passed":true},{"actual":[[0.0,1.0]],"check":"fixture 2","expected":[[1,0]],"passed":false},{"actual":[[1.0,0.0]],"check":"fixture 3","expected":[[0,1]],"passed":false},{"actual":[],"check":"fixture 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[0.5, 0.5]], \"expected\": [[0.5, 0.5]], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [[0.0, 1.0]], \"expected\": [[1, 0]], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [[1.0, 0.0]], \"expected\": [[0, 1]], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.246,"exit_code":1,"observations":[{"actual":[[1,1]],"check":"fixture 1","expected":[[0.5,0.5]],"passed":false},{"actual":[[2,0]],"check":"fixture 2","expected":[[1,0]],"passed":false},{"actual":[[0,2]],"check":"fixture 3","expected":[[0,1]],"passed":false},{"actual":[],"check":"fixture 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[1, 1]], \"expected\": [[0.5, 0.5]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[2, 0]], \"expected\": [[1, 0]], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [[0, 2]], \"expected\": [[0, 1]], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.486,"exit_code":0,"observations":[{"actual":[[0.5,0.5]],"check":"fixture 1","expected":[[0.5,0.5]],"passed":true},{"actual":[[1.0,0.0]],"check":"fixture 2","expected":[[1,0]],"passed":true},{"actual":[[0.0,1.0]],"check":"fixture 3","expected":[[0,1]],"passed":true},{"actual":[],"check":"fixture 4","expected":[],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[0.5, 0.5]], \"expected\": [[0.5, 0.5]], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [[1.0, 0.0]], \"expected\": [[1, 0]], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[0.0, 1.0]], \"expected\": [[0, 1]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}