{"abstract":"Symmetric minimum code is asymmetric.","category":"Model quantization arithmetic","checks":7,"contract":"Map by positive scale into the inclusive symmetric integer range [-qmax,qmax], with zero point zero. Inputs follow this explicit integer toy contract; ties use Python round-to-even where rounding is required.","contract_signature":"values, scale, qmax","evaluation_group":"quant-symmetric_quant","failed_approach":"The attempted code fixes lower saturation but truncates scaled values rather than using the declared midpoint rounding rule.","family":"w3-model-quantization-arithmetic-symmetric-range","id":"FA-98731","implementations":{"attempt":{"sha256":"39d24d89420383ef976dc843df03441f6cc8bcfc8c8e39409a34e28e23e78b77","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(values, scale, qmax):\n    return [max(-qmax,min(qmax,int(x/scale))) for x in values]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('lower endpoint',solve([-8],1,8),[-8])\ncheck('upper endpoint',solve([8],1,8),[8])\ncheck('below range',solve([-100],1,8),[-8])\ncheck('above range',solve([100],1,8),[8])\ncheck('empty',solve([],1,8),[])\ncheck('interior',solve([N],1,8),[N])\ncheck('fractional round',solve([3],2,8),[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":"966eeced159e73b5f40d41f01c6b184a4d4cbc90a29bc57572c3e6c12bff102d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(values, scale, qmax):\n    return [max(-qmax+1,min(qmax,round(x/scale))) for x in values]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('lower endpoint',solve([-8],1,8),[-8])\ncheck('upper endpoint',solve([8],1,8),[8])\ncheck('below range',solve([-100],1,8),[-8])\ncheck('above range',solve([100],1,8),[8])\ncheck('empty',solve([],1,8),[])\ncheck('interior',solve([N],1,8),[N])\ncheck('fractional round',solve([3],2,8),[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":"Toy scalar/list arithmetic only; it does not model a production quantizer, hardware instruction, or accuracy/performance gain. 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-model-quantization-arithmetic-symmetric-range","generated_at":"2026-09-30T16:48:16.278439+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic model isolates one quantization arithmetic contract from tensor storage and runtime kernels.","root_cause":"Map by positive scale into the inclusive symmetric integer range [-qmax,qmax], with zero point zero.","sha256":"1ab2fc27c4116baeaf443141097985638055875b4f7b51638c11d3c6ce8f735a","title":"Quantization: Symmetric minimum code is asymmetric · case 01","variant":1,"variant_policy":"The fixture code references N, supplied as 1 through 5. Fixed boundary checks may repeat. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":26.633,"exit_code":1,"observations":[{"actual":[-8],"check":"lower endpoint","expected":[-8],"passed":true},{"actual":[8],"check":"upper endpoint","expected":[8],"passed":true},{"actual":[-8],"check":"below range","expected":[-8],"passed":true},{"actual":[8],"check":"above range","expected":[8],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[1],"check":"interior","expected":[1],"passed":true},{"actual":[1],"check":"fractional round","expected":[2],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"lower endpoint\", \"actual\": [-8], \"expected\": [-8], \"passed\": true}, {\"check\": \"upper endpoint\", \"actual\": [8], \"expected\": [8], \"passed\": true}, {\"check\": \"below range\", \"actual\": [-8], \"expected\": [-8], \"passed\": true}, {\"check\": \"above range\", \"actual\": [8], \"expected\": [8], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"interior\", \"actual\": [1], \"expected\": [1], \"passed\": true}, {\"check\": \"fractional round\", \"actual\": [1], \"expected\": [2], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":26.584,"exit_code":1,"observations":[{"actual":[-7],"check":"lower endpoint","expected":[-8],"passed":false},{"actual":[8],"check":"upper endpoint","expected":[8],"passed":true},{"actual":[-7],"check":"below range","expected":[-8],"passed":false},{"actual":[8],"check":"above range","expected":[8],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[1],"check":"interior","expected":[1],"passed":true},{"actual":[2],"check":"fractional round","expected":[2],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"lower endpoint\", \"actual\": [-7], \"expected\": [-8], \"passed\": false}, {\"check\": \"upper endpoint\", \"actual\": [8], \"expected\": [8], \"passed\": true}, {\"check\": \"below range\", \"actual\": [-7], \"expected\": [-8], \"passed\": false}, {\"check\": \"above range\", \"actual\": [8], \"expected\": [8], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"interior\", \"actual\": [1], \"expected\": [1], \"passed\": true}, {\"check\": \"fractional round\", \"actual\": [2], \"expected\": [2], \"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."}}