{"abstract":"broadcasted singleton gets zero stride.","category":"Tensor stride and reshape semantics","checks":6,"contract":"Broadcast an input axis to target size; unchanged dimensions keep stride and expanded singleton axes get stride zero.","contract_signature":"shape, strides, target","evaluation_group":"tensor-broadcast-zero-stride","failed_approach":"A unit stride allows address advancement and makes expanded values incorrect.","family":"w3-tensor-stride-reshape-broadcast-zero-stride","id":"FA-98761","implementations":{"attempt":{"sha256":"5e6c780e7e5116e81b895b2762039448e973f1f13d10c0479ee21b78a6688fe9","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(shape, strides, target):\n    return list(target),[s if a==b else 1 for a,b,s in zip(shape,target,strides)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('expand row',solve([1,N],[1,1],[3,N]),([3,N],[0,1]))\ncheck('expand column',solve([N,1],[1,1],[N,4]),([N,4],[1,0]))\ncheck('unchanged',solve([2,3],[3,1],[2,3]),([2,3],[3,1]))\ncheck('two expansions',solve([1,1],[1,1],[4,3]),([4,3],[0,0]))\ncheck('already zero',solve([1,2],[0,1],[4,2]),([4,2],[0,1]))\ncheck('singleton target',solve([1],[7],[1]),([1],[7]))\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":"545e11caa878f488687323381ef1ba1b1a8eaab3f407334cf5798d65b8489f7d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(shape, strides, target):\n    return list(target),list(strides)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('expand row',solve([1,N],[1,1],[3,N]),([3,N],[0,1]))\ncheck('expand column',solve([N,1],[1,1],[N,4]),([N,4],[1,0]))\ncheck('unchanged',solve([2,3],[3,1],[2,3]),([2,3],[3,1]))\ncheck('two expansions',solve([1,1],[1,1],[4,3]),([4,3],[0,0]))\ncheck('already zero',solve([1,2],[0,1],[4,2]),([4,2],[0,1]))\ncheck('singleton target',solve([1],[7],[1]),([1],[7]))\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":"Self-contained integer metadata models only; no production framework compatibility or performance claim. 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-tensor-stride-reshape-broadcast-zero-stride","generated_at":"2026-09-30T16:48:16.724370+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Dense tensor views rely on consistent logical coordinates and physical storage addresses.","root_cause":"An expanded singleton axis must reuse one storage location rather than advance.","sha256":"b8abf76713c7233f556868e5b789df791b435b166a48a9bdb10acc21ff03c20e","title":"Tensor views: broadcasted singleton gets zero stride · 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":27.664,"exit_code":1,"observations":[{"actual":[[3,1],[1,1]],"check":"expand row","expected":[[3,1],[0,1]],"passed":false},{"actual":[[1,4],[1,1]],"check":"expand column","expected":[[1,4],[1,0]],"passed":false},{"actual":[[2,3],[3,1]],"check":"unchanged","expected":[[2,3],[3,1]],"passed":true},{"actual":[[4,3],[1,1]],"check":"two expansions","expected":[[4,3],[0,0]],"passed":false},{"actual":[[4,2],[1,1]],"check":"already zero","expected":[[4,2],[0,1]],"passed":false},{"actual":[[1],[7]],"check":"singleton target","expected":[[1],[7]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"expand row\", \"actual\": [[3, 1], [1, 1]], \"expected\": [[3, 1], [0, 1]], \"passed\": false}, {\"check\": \"expand column\", \"actual\": [[1, 4], [1, 1]], \"expected\": [[1, 4], [1, 0]], \"passed\": false}, {\"check\": \"unchanged\", \"actual\": [[2, 3], [3, 1]], \"expected\": [[2, 3], [3, 1]], \"passed\": true}, {\"check\": \"two expansions\", \"actual\": [[4, 3], [1, 1]], \"expected\": [[4, 3], [0, 0]], \"passed\": false}, {\"check\": \"already zero\", \"actual\": [[4, 2], [1, 1]], \"expected\": [[4, 2], [0, 1]], \"passed\": false}, {\"check\": \"singleton target\", \"actual\": [[1], [7]], \"expected\": [[1], [7]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":27.067,"exit_code":1,"observations":[{"actual":[[3,1],[1,1]],"check":"expand row","expected":[[3,1],[0,1]],"passed":false},{"actual":[[1,4],[1,1]],"check":"expand column","expected":[[1,4],[1,0]],"passed":false},{"actual":[[2,3],[3,1]],"check":"unchanged","expected":[[2,3],[3,1]],"passed":true},{"actual":[[4,3],[1,1]],"check":"two expansions","expected":[[4,3],[0,0]],"passed":false},{"actual":[[4,2],[0,1]],"check":"already zero","expected":[[4,2],[0,1]],"passed":true},{"actual":[[1],[7]],"check":"singleton target","expected":[[1],[7]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"expand row\", \"actual\": [[3, 1], [1, 1]], \"expected\": [[3, 1], [0, 1]], \"passed\": false}, {\"check\": \"expand column\", \"actual\": [[1, 4], [1, 1]], \"expected\": [[1, 4], [1, 0]], \"passed\": false}, {\"check\": \"unchanged\", \"actual\": [[2, 3], [3, 1]], \"expected\": [[2, 3], [3, 1]], \"passed\": true}, {\"check\": \"two expansions\", \"actual\": [[4, 3], [1, 1]], \"expected\": [[4, 3], [0, 0]], \"passed\": false}, {\"check\": \"already zero\", \"actual\": [[4, 2], [0, 1]], \"expected\": [[4, 2], [0, 1]], \"passed\": true}, {\"check\": \"singleton target\", \"actual\": [[1], [7]], \"expected\": [[1], [7]], \"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."}}