FA-14152 / Numerical aggregation / Member archive

Jointly observed pair summary: Truthy filtering discards legitimate zero observations. · case 02

The reduction disagrees with its explicit aggregation oracle.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Each row holds two integer values or None. Include a row only when both values are observed; zero is observed. Return [paired count, x sum, y sum, cross-product sum, squared-distance sum]. No imputation and no marginal-only contributions.

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 1	`[1, 1, 2, 2, 1]`	`[2, 1, 6, 2, 17]`	Failed

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

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