{"abstract":"Every PCM residual is added to the seed rather than prior reconstructed sample.","category":"PCM sample encoding","checks":8,"contract":"Reconstruct bounded delta-coded PCM from a seed and explicit sample-index resets before residual application, returning the continuation predictor.","contract_signature":"deltas, initial, reset_positions","evaluation_group":"s3-pcm-pcm-delta-reconstruction","failed_approach":"Subtracting residuals reverses the differential convention.","family":"s3-pcm-pcm-delta-reconstruction-delta-accumulate","id":"FA-49226","implementations":{"attempt":{"sha256":"b05083a660b472b0af2f2ff0f7cf296246b4300228a7d3d41b7c5e16d4aa5541","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(deltas, initial, reset_positions):\n    previous=initial\n    out=[]\n    for i,delta in enumerate(deltas):\n        if i in reset_positions:\n            previous=initial\n        previous-=delta\n        out.append(previous)\n    return [out,previous]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([2, -1, 3], 10, [])), [[12, 11, 14], 14])\ncheck('oracle 2', solve(*([1, 2, 3, 4], 5, [2])), [[6, 8, 8, 12], 12])\ncheck('oracle 3', solve(*([], 7, [])), [[], 7])\ncheck('oracle 4', solve(*([0, 0], -3, [0])), [[-3, -3], -3])\ncheck('oracle 5', solve(*([-2, 4, -1], 0, [1])), [[-2, 4, 3], 3])\ncheck('oracle 6', solve(*([3], 2, [])), [[5], 5])\ncheck('oracle 7', solve(*([1, 1, 1], 1, [0, 1, 2])), [[2, 2, 2], 2])\nif N == 1: check('variant packet 1', solve(*[[2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18], 18])\nif N == 2: check('variant packet 2', solve(*[[2, -1, 3, 2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18, 20, 19, 22], 22])\nif N == 3: check('variant packet 3', solve(*[[2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18, 20, 19, 22, 24, 23, 26], 26])\nif N == 4: check('variant packet 4', solve(*[[2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18, 20, 19, 22, 24, 23, 26, 28, 27, 30], 30])\nif N == 5: check('variant packet 5', solve(*[[2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18, 20, 19, 22, 24, 23, 26, 28, 27, 30, 32, 31, 34], 34])\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":"e3843bd62bcd73f412a2f943fe3c5bc273a62037d6ba7d68bdf5bf5aff37a78b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(deltas, initial, reset_positions):\n    previous=initial\n    out=[]\n    for i,delta in enumerate(deltas):\n        if i in reset_positions:\n            previous=initial\n        previous=initial+delta\n        out.append(previous)\n    return [out,previous]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([2, -1, 3], 10, [])), [[12, 11, 14], 14])\ncheck('oracle 2', solve(*([1, 2, 3, 4], 5, [2])), [[6, 8, 8, 12], 12])\ncheck('oracle 3', solve(*([], 7, [])), [[], 7])\ncheck('oracle 4', solve(*([0, 0], -3, [0])), [[-3, -3], -3])\ncheck('oracle 5', solve(*([-2, 4, -1], 0, [1])), [[-2, 4, 3], 3])\ncheck('oracle 6', solve(*([3], 2, [])), [[5], 5])\ncheck('oracle 7', solve(*([1, 1, 1], 1, [0, 1, 2])), [[2, 2, 2], 2])\nif N == 1: check('variant packet 1', solve(*[[2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18], 18])\nif N == 2: check('variant packet 2', solve(*[[2, -1, 3, 2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18, 20, 19, 22], 22])\nif N == 3: check('variant packet 3', solve(*[[2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18, 20, 19, 22, 24, 23, 26], 26])\nif N == 4: check('variant packet 4', solve(*[[2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18, 20, 19, 22, 24, 23, 26, 28, 27, 30], 30])\nif N == 5: check('variant packet 5', solve(*[[2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3], 10, []]), [[12, 11, 14, 16, 15, 18, 20, 19, 22, 24, 23, 26, 28, 27, 30, 32, 31, 34], 34])\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":"Stipulated finite model; no claim of hardware timing or full file-format conformance. 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":"s3-pcm-pcm-delta-reconstruction-delta-accumulate","generated_at":"2026-09-29T14:44:58.040035+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline PCM interchange uses these exact bounded packet and sample representation decisions.","root_cause":"Every PCM residual is added to the seed rather than prior reconstructed sample.","sha256":"de9632a5d5000e60020a6c668bf7b37e6ffadea1006dee19f14f0c4e2a592a9b","title":"Pcm delta reconstruction: delta accumulate · 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":41.33,"exit_code":1,"observations":[{"actual":[[8,9,6],6],"check":"oracle 1","expected":[[12,11,14],14],"passed":false},{"actual":[[4,2,2,-2],-2],"check":"oracle 2","expected":[[6,8,8,12],12],"passed":false},{"actual":[[],7],"check":"oracle 3","expected":[[],7],"passed":true},{"actual":[[-3,-3],-3],"check":"oracle 4","expected":[[-3,-3],-3],"passed":true},{"actual":[[2,-4,-3],-3],"check":"oracle 5","expected":[[-2,4,3],3],"passed":false},{"actual":[[-1],-1],"check":"oracle 6","expected":[[5],5],"passed":false},{"actual":[[0,0,0],0],"check":"oracle 7","expected":[[2,2,2],2],"passed":false},{"actual":[[8,9,6,4,5,2],2],"check":"variant packet 1","expected":[[12,11,14,16,15,18],18],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[8, 9, 6], 6], \"expected\": [[12, 11, 14], 14], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[4, 2, 2, -2], -2], \"expected\": [[6, 8, 8, 12], 12], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[], 7], \"expected\": [[], 7], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [[-3, -3], -3], \"expected\": [[-3, -3], -3], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[2, -4, -3], -3], \"expected\": [[-2, 4, 3], 3], \"passed\": false}, {\"check\": \"oracle 6\", \"actual\": [[-1], -1], \"expected\": [[5], 5], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[0, 0, 0], 0], \"expected\": [[2, 2, 2], 2], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [[8, 9, 6, 4, 5, 2], 2], \"expected\": [[12, 11, 14, 16, 15, 18], 18], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.986,"exit_code":1,"observations":[{"actual":[[12,9,13],13],"check":"oracle 1","expected":[[12,11,14],14],"passed":false},{"actual":[[6,7,8,9],9],"check":"oracle 2","expected":[[6,8,8,12],12],"passed":false},{"actual":[[],7],"check":"oracle 3","expected":[[],7],"passed":true},{"actual":[[-3,-3],-3],"check":"oracle 4","expected":[[-3,-3],-3],"passed":true},{"actual":[[-2,4,-1],-1],"check":"oracle 5","expected":[[-2,4,3],3],"passed":false},{"actual":[[5],5],"check":"oracle 6","expected":[[5],5],"passed":true},{"actual":[[2,2,2],2],"check":"oracle 7","expected":[[2,2,2],2],"passed":true},{"actual":[[12,9,13,12,9,13],13],"check":"variant packet 1","expected":[[12,11,14,16,15,18],18],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[12, 9, 13], 13], \"expected\": [[12, 11, 14], 14], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[6, 7, 8, 9], 9], \"expected\": [[6, 8, 8, 12], 12], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[], 7], \"expected\": [[], 7], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [[-3, -3], -3], \"expected\": [[-3, -3], -3], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[-2, 4, -1], -1], \"expected\": [[-2, 4, 3], 3], \"passed\": false}, {\"check\": \"oracle 6\", \"actual\": [[5], 5], \"expected\": [[5], 5], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[2, 2, 2], 2], \"expected\": [[2, 2, 2], 2], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[12, 9, 13, 12, 9, 13], 13], \"expected\": [[12, 11, 14, 16, 15, 18], 18], \"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."}}