{"abstract":"A shorter range drops trailing factors, or broadcasting repeats its last value.","category":"Spreadsheet calculation semantics","checks":6,"contract":"One-dimensional integer ranges must have equal lengths. Return pairwise product sum or #VALUE! for mismatched lengths; two empty ranges sum to zero.","contract_signature":"a, b","evaluation_group":"model-db65215fb9f6a1e7","failed_approach":"Repeating the last short-range value creates products for cells that were never supplied.","family":"z-spreadsheets-sumproduct-shape","id":"FA-11376","implementations":{"attempt":{"sha256":"6b24519dd7ff0c89ecf3c02f93b083bacd81fa62fac84d0cbe2a67d3540d791a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(a, b):\n    if not a or not b:\n        return 0\n    return sum(a[min(i,len(a)-1)] * b[min(i,len(b)-1)] for i in range(max(len(a),len(b))))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('short right range', solve([N,2],[3]), '#VALUE!')\ncheck('short left range', solve([N],[2,3]), '#VALUE!')\ncheck('empty right range', solve([N],[]), '#VALUE!')\ncheck('both empty', solve([],[]), 0)\ncheck('aligned signed products', solve([N,-2],[3,4]),3*N-8)\ncheck('zero factor retained', solve([N,0],[0,N]),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":"8313972c7c31130bebcfba5b7f5820adea1f80e4c9c4d195d4352ecee440ebd2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(a, b):\n    return sum(x*y for x,y in zip(a,b))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('short right range', solve([N,2],[3]), '#VALUE!')\ncheck('short left range', solve([N],[2,3]), '#VALUE!')\ncheck('empty right range', solve([N],[]), '#VALUE!')\ncheck('both empty', solve([],[]), 0)\ncheck('aligned signed products', solve([N,-2],[3,4]),3*N-8)\ncheck('zero factor retained', solve([N,0],[0,N]),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":" 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-spreadsheets-sumproduct-shape","generated_at":"2026-09-29T14:38:47.408481+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This isolated spreadsheet model makes cell semantics explicit; it does not claim compatibility with every workbook engine.","root_cause":"Zip truncation is accepted as range alignment.","sha256":"2310a882c4b9d5ff978dd4209bfe81a651965995342c76958f638f6fa147d847","title":"SUMPRODUCT silently truncates mismatched ranges · 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":42.906,"exit_code":1,"observations":[{"actual":9,"check":"short right range","expected":"#VALUE!","passed":false},{"actual":5,"check":"short left range","expected":"#VALUE!","passed":false},{"actual":0,"check":"empty right range","expected":"#VALUE!","passed":false},{"actual":0,"check":"both empty","expected":0,"passed":true},{"actual":-5,"check":"aligned signed products","expected":-5,"passed":true},{"actual":0,"check":"zero factor retained","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"short right range\", \"actual\": 9, \"expected\": \"#VALUE!\", \"passed\": false}, {\"check\": \"short left range\", \"actual\": 5, \"expected\": \"#VALUE!\", \"passed\": false}, {\"check\": \"empty right range\", \"actual\": 0, \"expected\": \"#VALUE!\", \"passed\": false}, {\"check\": \"both empty\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"aligned signed products\", \"actual\": -5, \"expected\": -5, \"passed\": true}, {\"check\": \"zero factor retained\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.1,"exit_code":1,"observations":[{"actual":3,"check":"short right range","expected":"#VALUE!","passed":false},{"actual":2,"check":"short left range","expected":"#VALUE!","passed":false},{"actual":0,"check":"empty right range","expected":"#VALUE!","passed":false},{"actual":0,"check":"both empty","expected":0,"passed":true},{"actual":-5,"check":"aligned signed products","expected":-5,"passed":true},{"actual":0,"check":"zero factor retained","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"short right range\", \"actual\": 3, \"expected\": \"#VALUE!\", \"passed\": false}, {\"check\": \"short left range\", \"actual\": 2, \"expected\": \"#VALUE!\", \"passed\": false}, {\"check\": \"empty right range\", \"actual\": 0, \"expected\": \"#VALUE!\", \"passed\": false}, {\"check\": \"both empty\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"aligned signed products\", \"actual\": -5, \"expected\": -5, \"passed\": true}, {\"check\": \"zero factor retained\", \"actual\": 0, \"expected\": 0, \"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."}}