FA-13193 / Numerical aggregation / Member archive

Maximum subarray block summary: The incoming local prefix is treated as a global prefix. · case 03

The reduction disagrees with its explicit aggregation oracle.

Member previewVariant 3 · 3 implementations · 9 checks per implementation

Case contract

Merge ordered disjoint integer blocks, preserving concatenation order. Return [total, maximum prefix sum, maximum suffix sum, maximum contiguous subarray sum]; empty subarrays are allowed and have sum zero.

Why this case matters

Exact bounded examples isolate a reduction defect without floating-point or external-service effects.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression 2	`[1, 3, 6, 7]`	`[1, 2, 6, 7]`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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