FA-12841 / Numerical aggregation / Open access
Signed channel totals: Positive and negative channels are collapsed before reporting. · case 01
The reduction disagrees with its explicit aggregation oracle.
ROOT CAUSE
Positive and negative channels are collapsed before reporting.
VERIFIED REPAIR
Preserve the signed channel totals contract at the identified reduction decision.
Unsuccessful approach: Absolute net magnitude still discards cancellation.
Case contract
Return [positive total, negative total, zero count] for an integer sequence; preserve signs and multiplicity.
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(xs):
return [max(0,sum(xs)),min(0,sum(xs)),xs.count(0)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('regression 1', solve(*([3, -2, 0, 3, -4, 0],)), [6, -6, 2])
check('regression 2', solve(*([],)), [0, 0, 0])
check('regression 3', solve(*([0, 0, 0],)), [0, 0, 3])
check('regression 4', solve(*([-8, -2],)), [0, -10, 0])
check('regression 5', solve(*([2, 2, 7],)), [11, 0, 0])
check("variable signed channels", solve([N,-N,0,N]), [2*N,-N,1])
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| regression 1 | [0, 0, 2] | [6, -6, 2] | Failed |
| regression 2 | [0, 0, 0] | [0, 0, 0] | Passed |
| regression 3 | [0, 0, 3] | [0, 0, 3] | Passed |
| regression 4 | [0, -10, 0] | [0, -10, 0] | Passed |
| regression 5 | [11, 0, 0] | [11, 0, 0] | Passed |
| variable signed channels | [1, 0, 1] | [2, -1, 1] | Failed |
SHA-256 / 424c2c61a4d47c308093828612c1647fc28b1ab845ef10c44d750745c6f2f903
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(xs):
return [abs(sum(xs)), -abs(sum(xs)), xs.count(0)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('regression 1', solve(*([3, -2, 0, 3, -4, 0],)), [6, -6, 2])
check('regression 2', solve(*([],)), [0, 0, 0])
check('regression 3', solve(*([0, 0, 0],)), [0, 0, 3])
check('regression 4', solve(*([-8, -2],)), [0, -10, 0])
check('regression 5', solve(*([2, 2, 7],)), [11, 0, 0])
check("variable signed channels", solve([N,-N,0,N]), [2*N,-N,1])
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| regression 1 | [0, 0, 2] | [6, -6, 2] | Failed |
| regression 2 | [0, 0, 0] | [0, 0, 0] | Passed |
| regression 3 | [0, 0, 3] | [0, 0, 3] | Passed |
| regression 4 | [10, -10, 0] | [0, -10, 0] | Failed |
| regression 5 | [11, -11, 0] | [11, 0, 0] | Failed |
| variable signed channels | [1, -1, 1] | [2, -1, 1] | Failed |
SHA-256 / 18ab568e02e90e8664ad78a8473d00c1acead4e2c764f5f062d1ea7b1024e49d
3 / The verified repair
Exit 0"""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(xs):
return [sum(x for x in xs if x>0), sum(x for x in xs if x<0), xs.count(0)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('regression 1', solve(*([3, -2, 0, 3, -4, 0],)), [6, -6, 2])
check('regression 2', solve(*([],)), [0, 0, 0])
check('regression 3', solve(*([0, 0, 0],)), [0, 0, 3])
check('regression 4', solve(*([-8, -2],)), [0, -10, 0])
check('regression 5', solve(*([2, 2, 7],)), [11, 0, 0])
check("variable signed channels", solve([N,-N,0,N]), [2*N,-N,1])
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| regression 1 | [6, -6, 2] | [6, -6, 2] | Passed |
| regression 2 | [0, 0, 0] | [0, 0, 0] | Passed |
| regression 3 | [0, 0, 3] | [0, 0, 3] | Passed |
| regression 4 | [0, -10, 0] | [0, -10, 0] | Passed |
| regression 5 | [11, 0, 0] | [11, 0, 0] | Passed |
| variable signed channels | [2, -1, 1] | [2, -1, 1] | Passed |
SHA-256 / 78a7955d2be7a67187873c2aed8d1ea9bd0e81f6fbe78c695ab3204ec5a175d8
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 2026-09-29T14:39:00.805096+00:00.
Case digest / 1b8a2a40e108383cd7b1e504c17ff05c6c9085b50d93ced14c2c64b3d20bbed3