FA-12426 / Laboratory measurement reporting / Open access

Carryover correction skips an intervening wash injection · case 01

Carryover correction skips an intervening wash injection.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The previous sample is used instead of the previous physical injection.

THE FAILURE

The previous sample is used instead of the previous physical injection.

Unsuccessful approach: Resetting predecessor to zero for a wash ignores its measured residual signal.

Case contract

For chronological [kind,raw] injections, subtract one tenth of the preceding raw injection from sample signals. First predecessor is zero. Washes emit nothing but update predecessor. Return Fraction strings; kinds sample or wash.

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
from fractions import Fraction
N = 1
observations = []
def solve(injections):
    previous=0
    out=[]
    for kind,raw in injections:
        if kind == 'sample':
            out.append(str(Fraction(raw)-Fraction(previous,10)))
            previous=raw
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('wash residual becomes predecessor', solve([('sample',100*N),('wash',10*N),('sample',20*N)]), [str(100*N),str(19*N)])
check('wash first', solve([('wash',10*N),('sample',20*N)]), [str(19*N)])
check('consecutive samples', solve([('sample',10*N),('sample',20*N)]), [str(10*N),str(19*N)])
check('last of multiple washes', solve([('wash',100*N),('wash',10*N),('sample',20*N)]), [str(19*N)])
check('only wash emits no report', solve([('wash',10*N)]), [])
check('empty run', solve([]), [])
check('first sample uncorrected', solve([('sample',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 fixture	Actual	Expected	Outcome
wash residual becomes predecessor	`['100', '10']`	`['100', '19']`	Failed
wash first	`['20']`	`['19']`	Failed
consecutive samples	`['10', '19']`	`['10', '19']`	Passed
last of multiple washes	`['20']`	`['19']`	Failed
only wash emits no report	`[]`	`[]`	Passed
empty run	`[]`	`[]`	Passed
first sample uncorrected	`['1']`	`['1']`	Passed

SHA-256 / b825d46ad240c9de65c08716c00f47ff48798f81b06ff31b9b313248f98a1bc1

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
from fractions import Fraction
N = 1
observations = []
def solve(injections):
    previous=0
    out=[]
    for kind,raw in injections:
        if kind == 'sample':
            out.append(str(Fraction(raw)-Fraction(previous,10)))
            previous=raw
        else:
            previous=0
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('wash residual becomes predecessor', solve([('sample',100*N),('wash',10*N),('sample',20*N)]), [str(100*N),str(19*N)])
check('wash first', solve([('wash',10*N),('sample',20*N)]), [str(19*N)])
check('consecutive samples', solve([('sample',10*N),('sample',20*N)]), [str(10*N),str(19*N)])
check('last of multiple washes', solve([('wash',100*N),('wash',10*N),('sample',20*N)]), [str(19*N)])
check('only wash emits no report', solve([('wash',10*N)]), [])
check('empty run', solve([]), [])
check('first sample uncorrected', solve([('sample',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 fixture	Actual	Expected	Outcome
wash residual becomes predecessor	`['100', '20']`	`['100', '19']`	Failed
wash first	`['20']`	`['19']`	Failed
consecutive samples	`['10', '19']`	`['10', '19']`	Passed
last of multiple washes	`['20']`	`['19']`	Failed
only wash emits no report	`[]`	`[]`	Passed
empty run	`[]`	`[]`	Passed
first sample uncorrected	`['1']`	`['1']`	Passed

SHA-256 / c85246d601194aa58cfe82145010670fa57a5c6840556bc030ae8e58d0f2ee74

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 7 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

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 2026-09-29T14:38:56.824393+00:00.

Case digest / 5bcb0d89b2d414bd0dcc0edb7737bd0ea2632e46e60cfddef97162ca60f6d6ea