FA-12401 / Laboratory measurement reporting / Open access

Diluted censored reports retain an aliquot detection limit · case 01

Diluted censored reports retain an aliquot detection limit.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

A less-than qualifier is attached to a concentration limit in the wrong sample basis.

VERIFIED REPAIR

Scale the limit for censored observations and the value for quantified observations.

Unsuccessful approach: Scaling every report using its limit replaces valid quantified values.

Case contract

For kind LT return [LT, limit*dilution]; for EQ return [EQ, value*dilution]. Numeric fields are integers, dilution positive, and LT ignores value.

Why this case matters

A deterministic synthetic laboratory reporting model isolates a software metadata contract; it is not a clinical procedure.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(kind, value, limit, dilution):
    return [kind, limit if kind == "LT" else value*dilution]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('diluted nondetect', solve('LT', 0, N, 4), ['LT',4*N])
check('quantified result', solve('EQ', 7*N, N, 4), ['EQ',28*N])
check('undiluted nondetect', solve('LT', 0, N, 1), ['LT',N])
check('zero quantified result', solve('EQ', 0, N, 2), ['EQ',0])
check('placeholder ignored', solve('LT', 999, N, 2), ['LT',2*N])
check('value at limit stays quantified', solve('EQ', N, N, 3), ['EQ',3*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 fixture	Actual	Expected	Outcome
diluted nondetect	`['LT', 1]`	`['LT', 4]`	Failed
quantified result	`['EQ', 28]`	`['EQ', 28]`	Passed
undiluted nondetect	`['LT', 1]`	`['LT', 1]`	Passed
zero quantified result	`['EQ', 0]`	`['EQ', 0]`	Passed
placeholder ignored	`['LT', 1]`	`['LT', 2]`	Failed
value at limit stays quantified	`['EQ', 3]`	`['EQ', 3]`	Passed

SHA-256 / 93c000b079f7810af7b679f380a9570d97a47bbd4c81784a1533cb3d8d26fdc4

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(kind, value, limit, dilution):
    return [kind, limit*dilution]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('diluted nondetect', solve('LT', 0, N, 4), ['LT',4*N])
check('quantified result', solve('EQ', 7*N, N, 4), ['EQ',28*N])
check('undiluted nondetect', solve('LT', 0, N, 1), ['LT',N])
check('zero quantified result', solve('EQ', 0, N, 2), ['EQ',0])
check('placeholder ignored', solve('LT', 999, N, 2), ['LT',2*N])
check('value at limit stays quantified', solve('EQ', N, N, 3), ['EQ',3*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 fixture	Actual	Expected	Outcome
diluted nondetect	`['LT', 4]`	`['LT', 4]`	Passed
quantified result	`['EQ', 4]`	`['EQ', 28]`	Failed
undiluted nondetect	`['LT', 1]`	`['LT', 1]`	Passed
zero quantified result	`['EQ', 2]`	`['EQ', 0]`	Failed
placeholder ignored	`['LT', 2]`	`['LT', 2]`	Passed
value at limit stays quantified	`['EQ', 3]`	`['EQ', 3]`	Passed

SHA-256 / 868c274de41c6596b372e89b5200f98b80798ef8222db13c1f23b52591674e17

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(kind, value, limit, dilution):
    return [kind, (limit if kind == "LT" else value)*dilution]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('diluted nondetect', solve('LT', 0, N, 4), ['LT',4*N])
check('quantified result', solve('EQ', 7*N, N, 4), ['EQ',28*N])
check('undiluted nondetect', solve('LT', 0, N, 1), ['LT',N])
check('zero quantified result', solve('EQ', 0, N, 2), ['EQ',0])
check('placeholder ignored', solve('LT', 999, N, 2), ['LT',2*N])
check('value at limit stays quantified', solve('EQ', N, N, 3), ['EQ',3*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 fixture	Actual	Expected	Outcome
diluted nondetect	`['LT', 4]`	`['LT', 4]`	Passed
quantified result	`['EQ', 28]`	`['EQ', 28]`	Passed
undiluted nondetect	`['LT', 1]`	`['LT', 1]`	Passed
zero quantified result	`['EQ', 0]`	`['EQ', 0]`	Passed
placeholder ignored	`['LT', 2]`	`['LT', 2]`	Passed
value at limit stays quantified	`['EQ', 3]`	`['EQ', 3]`	Passed

SHA-256 / 25191dd8930b834668f82c6a3d5c6619c0673adf467b6cc59a5f642d8b7a441c

Verification & scope

Synthetic integer/rational fixtures only; no instrument validation or clinical interpretation. 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 2026-09-29T14:38:56.601139+00:00.

Case digest / a831fec089b83b2680b5d3d7e812a1fad5154e023ba8cb61e20ad709641218b6