FAILURE MAP
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FA-13446 / Numerical aggregation / Open access

Empirical transport distance: The largest interval contribution replaces integrated area. · case 01

The reduction disagrees with its explicit aggregation oracle.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The largest interval contribution replaces integrated area.

THE FAILURE

The largest interval contribution replaces integrated area.

Unsuccessful approach: A maximum CDF difference is dimensionless and omits integration.

Case contract

For nonempty integer samples with equal total probability after separate normalization, return integral of absolute CDF difference over the real line as a Fraction string. Empty either side returns None.

Why this case matters

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

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
from fractions import Fraction
from collections import Counter, defaultdict
import math
import itertools
N = 1
observations = []
def solve(a, b):
    if not a or not b: return None
    ca,cb=Counter(a),Counter(b)
    points=sorted(set(ca)|set(cb))
    pa=pb=Fraction(0)
    area=Fraction(0)
    for i,x in enumerate(points[:-1]):
        pa+=Fraction(ca[x],len(a))
        pb+=Fraction(cb[x],len(b))
        area=max(area,abs(pa-pb)*(points[i+1]-x))
    return str(area)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('regression 1', solve(*([0, 0, 9], [1, 4])), '17/6')
check('regression 2', solve(*([2], [7])), '5')
check('regression 3', solve(*([1, 2], [1, 2])), '0')
check('regression 4', solve(*([], [1])), None)
check('regression 5', solve(*([-8, -1, 4], [-3, 9, 9])), '20/3')
check('regression 6', solve(*([0, 2, 8], [0, 8])), '4/3')
check('regression 7', solve(*([0, 10], [4, 6])), '4')
check("variable transport span",solve([0],[N]),str(N))
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression 15/317/6Failed
regression 255Passed
regression 300Passed
regression 4NoneNonePassed
regression 510/320/3Failed
regression 614/3Failed
regression 724Failed
variable transport span11Passed

SHA-256 / 743e2fd0ec0da8dc35eb0e88b8c57e2c830de9c2b9fa4b47e2b5d8f67c2f6655

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
from fractions import Fraction
from collections import Counter, defaultdict
import math
import itertools
N = 1
observations = []
def solve(a, b):
    if not a or not b: return None
    ca,cb=Counter(a),Counter(b)
    points=sorted(set(ca)|set(cb))
    pa=pb=Fraction(0)
    area=Fraction(0)
    for i,x in enumerate(points[:-1]):
        pa+=Fraction(ca[x],len(a))
        pb+=Fraction(cb[x],len(b))
        area=max(area,abs(pa-pb))
    return str(area)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('regression 1', solve(*([0, 0, 9], [1, 4])), '17/6')
check('regression 2', solve(*([2], [7])), '5')
check('regression 3', solve(*([1, 2], [1, 2])), '0')
check('regression 4', solve(*([], [1])), None)
check('regression 5', solve(*([-8, -1, 4], [-3, 9, 9])), '20/3')
check('regression 6', solve(*([0, 2, 8], [0, 8])), '4/3')
check('regression 7', solve(*([0, 10], [4, 6])), '4')
check("variable transport span",solve([0],[N]),str(N))
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression 12/317/6Failed
regression 215Failed
regression 300Passed
regression 4NoneNonePassed
regression 52/320/3Failed
regression 61/64/3Failed
regression 71/24Failed
variable transport span11Passed

SHA-256 / e64b9d7f0946162a26ae73e750faa69b872a83386d8df90d5440fe782195f7e2

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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Verification & scope

Small offline integer/rational inputs only; no performance, statistical inference, or production-library conformance 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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:39:07.201975+00:00.

Case digest / ffa25745ba8d0ffc231d247774a1b0c9cba7167b0fb63bbc6d7d4596fd109ec4