{"abstract":"stepped slice multiplies stride.","category":"Tensor stride and reshape semantics","checks":6,"contract":"Positive-step slice length is ceil(max(0,stop-start)/step), offset advances by start stride, new stride multiplies by step.","contract_signature":"shape, strides, offset, axis, start, stop, step","evaluation_group":"tensor-slice-stride-step","failed_approach":"Floor division drops a final selected element when the interval is not step-divisible.","family":"w3-tensor-stride-reshape-slice-stride-step","id":"FA-98826","implementations":{"attempt":{"sha256":"93aea4d6b4a8b6f5312b66bff5eab4491751cd454ae7fe6d48d75913ab364fa1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(shape, strides, offset, axis, start, stop, step):\n    out=list(shape); out[axis]=max(0,(stop-start)//step)\n    s=list(strides); s[axis]*=step\n    return out,s,offset+start*strides[axis]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('odd length',solve([N+5],[2],4,0,1,N+4,2),([((N+3)+1)//2],[4],6))\ncheck('unit step',solve([5],[3],1,0,1,4,1),([3],[3],4))\ncheck('empty slice',solve([5],[2],7,0,3,3,2),([0],[4],13))\ncheck('single element',solve([4],[5],0,0,2,3,3),([1],[15],10))\ncheck('overshoot stop',solve([N],[1],2,0,0,N,2),([(N+1)//2],[2],2))\ncheck('start at end',solve([4],[3],5,0,4,4,2),([0],[6],17))\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":"508e1346b906058f9e35eed1d007d5d2a6ce23016b9467427499102f54f14676","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(shape, strides, offset, axis, start, stop, step):\n    out=list(shape); out[axis]=max(0,stop-start)\n    s=list(strides); s[axis]*=step\n    return out,s,offset+start*strides[axis]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('odd length',solve([N+5],[2],4,0,1,N+4,2),([((N+3)+1)//2],[4],6))\ncheck('unit step',solve([5],[3],1,0,1,4,1),([3],[3],4))\ncheck('empty slice',solve([5],[2],7,0,3,3,2),([0],[4],13))\ncheck('single element',solve([4],[5],0,0,2,3,3),([1],[15],10))\ncheck('overshoot stop',solve([N],[1],2,0,0,N,2),([(N+1)//2],[2],2))\ncheck('start at end',solve([4],[3],5,0,4,4,2),([0],[6],17))\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-slice-stride-step","generated_at":"2026-09-30T16:48:17.164828+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":"Stepped slices retain fewer elements than the raw interval length suggests.","sha256":"f92bb05e62989c3d6029af46574646dabb6f3639313115a0488842bbe4df0e92","title":"Tensor views: stepped slice multiplies 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":27.186,"exit_code":1,"observations":[{"actual":[[2],[4],6],"check":"odd length","expected":[[2],[4],6],"passed":true},{"actual":[[3],[3],4],"check":"unit step","expected":[[3],[3],4],"passed":true},{"actual":[[0],[4],13],"check":"empty slice","expected":[[0],[4],13],"passed":true},{"actual":[[0],[15],10],"check":"single element","expected":[[1],[15],10],"passed":false},{"actual":[[0],[2],2],"check":"overshoot stop","expected":[[1],[2],2],"passed":false},{"actual":[[0],[6],17],"check":"start at end","expected":[[0],[6],17],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"odd length\", \"actual\": [[2], [4], 6], \"expected\": [[2], [4], 6], \"passed\": true}, {\"check\": \"unit step\", \"actual\": [[3], [3], 4], \"expected\": [[3], [3], 4], \"passed\": true}, {\"check\": \"empty slice\", \"actual\": [[0], [4], 13], \"expected\": [[0], [4], 13], \"passed\": true}, {\"check\": \"single element\", \"actual\": [[0], [15], 10], \"expected\": [[1], [15], 10], \"passed\": false}, {\"check\": \"overshoot stop\", \"actual\": [[0], [2], 2], \"expected\": [[1], [2], 2], \"passed\": false}, {\"check\": \"start at end\", \"actual\": [[0], [6], 17], \"expected\": [[0], [6], 17], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":27.555,"exit_code":1,"observations":[{"actual":[[4],[4],6],"check":"odd length","expected":[[2],[4],6],"passed":false},{"actual":[[3],[3],4],"check":"unit step","expected":[[3],[3],4],"passed":true},{"actual":[[0],[4],13],"check":"empty slice","expected":[[0],[4],13],"passed":true},{"actual":[[1],[15],10],"check":"single element","expected":[[1],[15],10],"passed":true},{"actual":[[1],[2],2],"check":"overshoot stop","expected":[[1],[2],2],"passed":true},{"actual":[[0],[6],17],"check":"start at end","expected":[[0],[6],17],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"odd length\", \"actual\": [[4], [4], 6], \"expected\": [[2], [4], 6], \"passed\": false}, {\"check\": \"unit step\", \"actual\": [[3], [3], 4], \"expected\": [[3], [3], 4], \"passed\": true}, {\"check\": \"empty slice\", \"actual\": [[0], [4], 13], \"expected\": [[0], [4], 13], \"passed\": true}, {\"check\": \"single element\", \"actual\": [[1], [15], 10], \"expected\": [[1], [15], 10], \"passed\": true}, {\"check\": \"overshoot stop\", \"actual\": [[1], [2], 2], \"expected\": [[1], [2], 2], \"passed\": true}, {\"check\": \"start at end\", \"actual\": [[0], [6], 17], \"expected\": [[0], [6], 17], \"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."}}