FAILURE MAP
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FA-64891 / Epidemic compartment models / Open access

SEIR daily symptom-onset incidence: removal source · case 01

Newly symptomatic people recover in the same day they become infectious.

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

ROOT CAUSE

Removal applies to prevalence plus today's onsets, whereas the Euler step uses start-of-day I.

VERIFIED REPAIR

Restore the removal source rule: `removal = gamma * i`.

Unsuccessful approach: Removing only a fraction of today's onsets ignores the existing infectious prevalence.

Case contract

Daily forward-Euler SEIR with sigma=1/latent_days and gamma=1/infectious_days; only I transmits (beta*S*I/pop); seeds start in E and are part of pop; return [daily E->I onsets rounded to 4, total population rounded to 4], or None for non-positive durations or population.

Why this case matters

Compartmental epidemic calculations drive outbreak forecasts, vaccine targets and hospital planning; a single wrong flow, rate conversion or boundary silently changes every downstream number.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(beta, latent_days, infectious_days, pop, e0, days):
    if latent_days <= 0 or infectious_days <= 0 or pop <= 0:
        return None
    sigma = 1.0 / latent_days
    gamma = 1.0 / infectious_days
    s, e, i, r = float(pop - e0), float(e0), 0.0, 0.0
    incidence = []
    for day in range(days):
        exposure = beta * s * i / pop
        onset = sigma * e
        removal = gamma * (i + onset)
        s -= exposure
        e += exposure - onset
        i += onset - removal
        r += removal
        incidence.append(round(onset, 4))
    return [incidence, round(s + e + i + r, 4)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('regression: measles-like long latency',
   (1.5, 8, 7, 5000, 5, 12),
   [[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]),
  ('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None)],
 [('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed', (0.9, 4, 3, 100, 60, 6), [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0]),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed', (0.9, 4, 3, 100, 60, 6), [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0]),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('regression: measles-like long latency',
   (1.5, 8, 7, 5000, 5, 12),
   [[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]),
  ('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed',
   (0.9, 4, 3, 100, 60, 6),
   [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0])]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
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: influenza-like 2 day latency[[5.0, 2.5, 2.24, 2.2727, 2.3446, 2.4228, 2.5028, 2.5841], 1000.0][[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]Failed
regression: measles-like long latency[[0.625, 0.5469, 0.5789, 0.6803, 0.8371, 1.0488, 1.3229, 1.6727, 2.1166, 2.6786, 3.3895, 4.2877], 5000.0][[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]Failed
regression: one-day latency[[4.0, 0.0, 1.176, 0.8767, 0.9967, 0.9974], 200.0][[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]Failed
control: no transmission[[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0][[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]Passed
control: boundary zero days[[], 100.0][[], 100.0]Passed
control: invalid zero latencyNoneNonePassed
control: invalid zero populationNoneNonePassed

SHA-256 / 846ed7b0ca7b067b71787fa6f47233e50bc6b1d83f948e64d51764b3cc3ac1dc

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(beta, latent_days, infectious_days, pop, e0, days):
    if latent_days <= 0 or infectious_days <= 0 or pop <= 0:
        return None
    sigma = 1.0 / latent_days
    gamma = 1.0 / infectious_days
    s, e, i, r = float(pop - e0), float(e0), 0.0, 0.0
    incidence = []
    for day in range(days):
        exposure = beta * s * i / pop
        onset = sigma * e
        removal = gamma * onset
        s -= exposure
        e += exposure - onset
        i += onset - removal
        r += removal
        incidence.append(round(onset, 4))
    return [incidence, round(s + e + i + r, 4)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('regression: measles-like long latency',
   (1.5, 8, 7, 5000, 5, 12),
   [[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]),
  ('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None)],
 [('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed', (0.9, 4, 3, 100, 60, 6), [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0]),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed', (0.9, 4, 3, 100, 60, 6), [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0]),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('regression: measles-like long latency',
   (1.5, 8, 7, 5000, 5, 12),
   [[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]),
  ('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed',
   (0.9, 4, 3, 100, 60, 6),
   [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0])]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
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: influenza-like 2 day latency[[5.0, 2.5, 2.24, 2.602, 3.2199, 4.032, 5.0549, 6.3298], 1000.0][[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]Failed
regression: measles-like long latency[[0.625, 0.5469, 0.5789, 0.6946, 0.8888, 1.1699, 1.5582, 2.0848, 2.794, 3.7461, 5.0218, 6.7286], 5000.0][[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]Failed
regression: one-day latency[[4.0, 0.0, 1.176, 1.1689, 1.5035, 1.8288], 200.0][[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]Failed
control: no transmission[[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0][[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]Passed
control: boundary zero days[[], 100.0][[], 100.0]Passed
control: invalid zero latencyNoneNonePassed
control: invalid zero populationNoneNonePassed

SHA-256 / 5720f3e59513d883717d184927500bb4beee6b78eebc74bc61033d859fa75ccb

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(beta, latent_days, infectious_days, pop, e0, days):
    if latent_days <= 0 or infectious_days <= 0 or pop <= 0:
        return None
    sigma = 1.0 / latent_days
    gamma = 1.0 / infectious_days
    s, e, i, r = float(pop - e0), float(e0), 0.0, 0.0
    incidence = []
    for day in range(days):
        exposure = beta * s * i / pop
        onset = sigma * e
        removal = gamma * i
        s -= exposure
        e += exposure - onset
        i += onset - removal
        r += removal
        incidence.append(round(onset, 4))
    return [incidence, round(s + e + i + r, 4)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('regression: measles-like long latency',
   (1.5, 8, 7, 5000, 5, 12),
   [[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]),
  ('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None)],
 [('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed', (0.9, 4, 3, 100, 60, 6), [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0]),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed', (0.9, 4, 3, 100, 60, 6), [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0]),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: influenza-like 2 day latency',
   (0.6, 2, 3, 1000, 10, 8),
   [[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]),
  ('regression: measles-like long latency',
   (1.5, 8, 7, 5000, 5, 12),
   [[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]),
  ('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('regression: long infectious period',
   (0.3, 5, 14, 2000, 50, 10),
   [[10.0, 8.0, 6.985, 6.5977, 6.6203, 6.9212, 7.4223, 8.0781, 8.8635, 9.7655], 2000.0])],
 [('regression: one-day latency', (0.4, 1, 4, 200, 4, 6), [[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]),
  ('control: no transmission',
   (0.0, 3, 5, 100, 20, 6),
   [[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]),
  ('control: boundary zero days', (0.5, 3, 5, 100, 5, 0), [[], 100.0]),
  ('control: invalid zero latency', (0.5, 0, 5, 100, 5, 5), None),
  ('control: invalid zero population', (0.5, 2, 5, 0, 0, 5), None),
  ('regression: fractional latency',
   (0.8, 1.5, 2.5, 300, 6, 7),
   [[4.0, 1.3333, 2.5351, 2.7755, 3.3698, 3.9741, 4.6871], 300.0]),
  ('regression: large seed',
   (0.9, 4, 3, 100, 60, 6),
   [[15.0, 11.25, 9.7875, 8.9949, 8.2544, 7.4237], 100.0])]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
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: influenza-like 2 day latency[[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0][[5.0, 2.5, 2.735, 3.0948, 3.5019, 3.9584, 4.4687, 5.0378], 1000.0]Passed
regression: measles-like long latency[[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0][[0.625, 0.5469, 0.5956, 0.7239, 0.9186, 1.1836, 1.5328, 1.9882, 2.5798, 3.3471, 4.3413, 5.6281], 5000.0]Passed
regression: one-day latency[[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0][[4.0, 0.0, 1.568, 1.1666, 1.4758, 1.5459], 200.0]Passed
control: no transmission[[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0][[6.6667, 4.4444, 2.963, 1.9753, 1.3169, 0.8779], 100.0]Passed
control: boundary zero days[[], 100.0][[], 100.0]Passed
control: invalid zero latencyNoneNonePassed
control: invalid zero populationNoneNonePassed

SHA-256 / 7beb58fba9bdd732135f3db794de27365054a60243c8799256eb58e180e994a1

Verification & scope

Deterministic bounded teaching model with a stipulated contract; not a validated scientific or public-health modelling library. 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 2026-09-29T14:47:28.849800+00:00.

Case digest / fbbcd58f734bec24b86945e5c89e97ecdca67fb02dc88a9eecacf520cf4a90fb