FAILURE MAP
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FA-13581 / Numerical aggregation / Open access

Timestamp half decayed mass: Future events are clamped to zero age and included. · case 01

The reduction disagrees with its explicit aggregation oracle.

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

ROOT CAUSE

Future events are clamped to zero age and included.

VERIFIED REPAIR

Preserve the timestamp half decayed mass contract at the identified reduction decision.

Unsuccessful approach: Assigning a one-step age to a future observation still leaks unavailable mass.

Case contract

Each [integer timestamp, integer contribution] independently contributes value/2**age at integer query now; exclude future events. Same-time events are independent additive contributions. Return exact Fraction string.

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(events, now):
    out=Fraction(0)
    for t,value in events:
        t=min(t,now)
        out+=Fraction(value,2**(now-t))
    return str(out)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('regression 1', solve(*([(0, 8), (2, 4)], 3)), '3')
check('regression 2', solve(*([], 4)), '0')
check('regression 3', solve(*([(5, 3)], 4)), '0')
check('regression 4', solve(*([(3, -4), (3, 8)], 3)), '4')
check('regression 5', solve(*([(0, 3), (1, 2), (1, 2)], 2)), '11/4')
check('regression 6', solve(*([(-2, 8), (0, -1)], 1)), '1/2')
check('regression 7', solve(*([(4, 9), (0, 16)], 4)), '10')
check("variable age",solve([(0,2**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 fixtureActualExpectedOutcome
regression 133Passed
regression 200Passed
regression 330Failed
regression 444Passed
regression 511/411/4Passed
regression 61/21/2Passed
regression 71010Passed
variable age11Passed

SHA-256 / d36ec7bdf9b78e309b7934e29bad4272181e71705c15e078487fe5f028229440

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(events, now):
    out=Fraction(0)
    for t,value in events:
        if t>now: t=now-1
        out+=Fraction(value,2**(now-t))
    return str(out)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('regression 1', solve(*([(0, 8), (2, 4)], 3)), '3')
check('regression 2', solve(*([], 4)), '0')
check('regression 3', solve(*([(5, 3)], 4)), '0')
check('regression 4', solve(*([(3, -4), (3, 8)], 3)), '4')
check('regression 5', solve(*([(0, 3), (1, 2), (1, 2)], 2)), '11/4')
check('regression 6', solve(*([(-2, 8), (0, -1)], 1)), '1/2')
check('regression 7', solve(*([(4, 9), (0, 16)], 4)), '10')
check("variable age",solve([(0,2**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 fixtureActualExpectedOutcome
regression 133Passed
regression 200Passed
regression 33/20Failed
regression 444Passed
regression 511/411/4Passed
regression 61/21/2Passed
regression 71010Passed
variable age11Passed

SHA-256 / 63ffab6b0f0730b2c269e7ba7c710ca5294308beef4602fee40335549de13cda

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(events, now):
    out=Fraction(0)
    for t,value in events:
        if t>now: continue
        out+=Fraction(value,2**(now-t))
    return str(out)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('regression 1', solve(*([(0, 8), (2, 4)], 3)), '3')
check('regression 2', solve(*([], 4)), '0')
check('regression 3', solve(*([(5, 3)], 4)), '0')
check('regression 4', solve(*([(3, -4), (3, 8)], 3)), '4')
check('regression 5', solve(*([(0, 3), (1, 2), (1, 2)], 2)), '11/4')
check('regression 6', solve(*([(-2, 8), (0, -1)], 1)), '1/2')
check('regression 7', solve(*([(4, 9), (0, 16)], 4)), '10')
check("variable age",solve([(0,2**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 fixtureActualExpectedOutcome
regression 133Passed
regression 200Passed
regression 300Passed
regression 444Passed
regression 511/411/4Passed
regression 61/21/2Passed
regression 71010Passed
variable age11Passed

SHA-256 / 1e2dbd9dc2732119fd3166906d82ac3d8c75f01596f3ed96e684181e9366e44f

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 2026-09-29T14:39:08.587770+00:00.

Case digest / f585214cb08b1137bc28ca4545daa9d10881cab24d0f17a26345dce2d95ea0cd