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FA-68716 / Toll and parking fee computation / Open access

EV charging session and idle fee: the minimum applies only to the energy charge · case 01

EV charging session and idle fee returns a wrong result when the minimum applies only to the energy charge.

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

ROOT CAUSE

The session fee is added on top of the minimum instead of counting toward it.

THE FAILURE

The session fee is added on top of the minimum instead of counting toward it.

Unsuccessful approach: Applying the minimum to energy only ignores idle fees that already exceed it.

Case contract

Input {plug_in, charge_end, unplug (minutes), wh, price_per_kwh, idle_grace, idle_rate (per started 10 min), idle_cap, session_fee, min_fee}. Energy = ceil(wh*price/1000). Idle minutes = max(0, unplug - charge_end - grace); idle fee = min(idle_cap, started 10-minute blocks * idle_rate). Total = max(min_fee, session_fee + energy + idle). Return {energy, idle, total}.

Why this case matters

Fee engines bill customers in integer cents; a wrong boundary, rounding stage or cap scope silently over- or under-charges.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    energy = -(-x['wh'] * x['price_per_kwh'] // 1000)
    idle = max(0, x['unplug'] - x['charge_end'] - x['idle_grace'])
    idle_fee = min(x['idle_cap'], -(-idle // 10) * x['idle_rate'])
    total = x['session_fee'] + energy + idle_fee
    return {'energy': energy, 'idle': idle_fee, 'total': x['session_fee'] + max(x['min_fee'], energy + idle_fee)}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 93, 'charge_end': 112, 'unplug': 312, 'wh': 46598, 'price_per_kwh': 35, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 0, 'min_fee': 500}, {'energy': 1631, 'idle': 1900, 'total': 3531}), ({'plug_in': 548, 'charge_end': 701, 'unplug': 706, 'wh': 9990, 'price_per_kwh': 29, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 500}, {'energy': 290, 'idle': 0, 'total': 500}), ({'plug_in': 502, 'charge_end': 683, 'unplug': 698, 'wh': 5462, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 50, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 300}, {'energy': 246, 'idle': 50, 'total': 300}), ({'plug_in': 119, 'charge_end': 199, 'unplug': 215, 'wh': 5114, 'price_per_kwh': 29, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 100, 'min_fee': 500}, {'energy': 149, 'idle': 100, 'total': 500}), ({'plug_in': 74, 'charge_end': 111, 'unplug': 171, 'wh': 4221, 'price_per_kwh': 29, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 500}, {'energy': 123, 'idle': 200, 'total': 500}), ({'plug_in': 585, 'charge_end': 800, 'unplug': 810, 'wh': 39441, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 2000, 'session_fee': 0, 'min_fee': 500}, {'energy': 1381, 'idle': 0, 'total': 1381}), ({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024})], [({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024}), ({'plug_in': 4, 'charge_end': 296, 'unplug': 312, 'wh': 3717, 'price_per_kwh': 52, 'idle_grace': 10, 'idle_rate': 40, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 500}, {'energy': 194, 'idle': 40, 'total': 500}), ({'plug_in': 73, 'charge_end': 83, 'unplug': 283, 'wh': 4230, 'price_per_kwh': 35, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 100, 'min_fee': 200}, {'energy': 149, 'idle': 1000, 'total': 1249}), ({'plug_in': 115, 'charge_end': 331, 'unplug': 346, 'wh': 4709, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 200}, {'energy': 245, 'idle': 0, 'total': 395}), ({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 490, 'charge_end': 569, 'unplug': 569, 'wh': 4974, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 100, 'min_fee': 300}, {'energy': 259, 'idle': 0, 'total': 359}), ({'plug_in': 157, 'charge_end': 214, 'unplug': 274, 'wh': 2276, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 50, 'idle_cap': 1000, 'session_fee': 150, 'min_fee': 500}, {'energy': 103, 'idle': 250, 'total': 503}), ({'plug_in': 230, 'charge_end': 290, 'unplug': 306, 'wh': 27281, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 300}, {'energy': 1228, 'idle': 100, 'total': 1478})], [({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 361, 'charge_end': 626, 'unplug': 626, 'wh': 29818, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 150, 'min_fee': 300}, {'energy': 1551, 'idle': 0, 'total': 1701}), ({'plug_in': 58, 'charge_end': 244, 'unplug': 260, 'wh': 4184, 'price_per_kwh': 45, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 100, 'min_fee': 300}, {'energy': 189, 'idle': 100, 'total': 389}), ({'plug_in': 34, 'charge_end': 215, 'unplug': 215, 'wh': 13150, 'price_per_kwh': 35, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 100, 'min_fee': 500}, {'energy': 461, 'idle': 0, 'total': 561}), ({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024}), ({'plug_in': 437, 'charge_end': 628, 'unplug': 628, 'wh': 6615, 'price_per_kwh': 45, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 298, 'idle': 0, 'total': 398}), ({'plug_in': 86, 'charge_end': 283, 'unplug': 288, 'wh': 13385, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 697, 'idle': 0, 'total': 697}), ({'plug_in': 433, 'charge_end': 493, 'unplug': 893, 'wh': 1131, 'price_per_kwh': 45, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 2000, 'session_fee': 0, 'min_fee': 200}, {'energy': 51, 'idle': 1560, 'total': 1611})], [({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024}), ({'plug_in': 63, 'charge_end': 346, 'unplug': 406, 'wh': 5005, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 500}, {'energy': 176, 'idle': 250, 'total': 576}), ({'plug_in': 197, 'charge_end': 253, 'unplug': 263, 'wh': 7897, 'price_per_kwh': 45, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 100, 'min_fee': 500}, {'energy': 356, 'idle': 0, 'total': 500}), ({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 484, 'charge_end': 672, 'unplug': 682, 'wh': 3159, 'price_per_kwh': 52, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 200}, {'energy': 165, 'idle': 0, 'total': 315}), ({'plug_in': 540, 'charge_end': 691, 'unplug': 691, 'wh': 40240, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 300}, {'energy': 1409, 'idle': 0, 'total': 1559}), ({'plug_in': 530, 'charge_end': 706, 'unplug': 722, 'wh': 19196, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 200}, {'energy': 557, 'idle': 100, 'total': 757}), ({'plug_in': 103, 'charge_end': 177, 'unplug': 377, 'wh': 8629, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 0, 'min_fee': 500}, {'energy': 389, 'idle': 760, 'total': 1149})], [({'plug_in': 537, 'charge_end': 679, 'unplug': 704, 'wh': 2203, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 64, 'idle': 200, 'total': 364}), ({'plug_in': 358, 'charge_end': 474, 'unplug': 484, 'wh': 14178, 'price_per_kwh': 29, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 2000, 'session_fee': 150, 'min_fee': 500}, {'energy': 412, 'idle': 0, 'total': 562}), ({'plug_in': 193, 'charge_end': 361, 'unplug': 386, 'wh': 58152, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 300}, {'energy': 3024, 'idle': 40, 'total': 3064}), ({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 80, 'charge_end': 341, 'unplug': 346, 'wh': 6794, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 500}, {'energy': 238, 'idle': 0, 'total': 500}), ({'plug_in': 473, 'charge_end': 503, 'unplug': 519, 'wh': 7069, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 0, 'min_fee': 500}, {'energy': 319, 'idle': 100, 'total': 500}), ({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024}), ({'plug_in': 411, 'charge_end': 481, 'unplug': 541, 'wh': 51535, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 500}, {'energy': 2680, 'idle': 250, 'total': 3080})]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('fee oracle' + ' %d' % i, 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
fee oracle 0{'energy': 438, 'idle': 50, 'total': 588}{'energy': 438, 'idle': 50, 'total': 588}Passed
fee oracle 1{'energy': 1631, 'idle': 1900, 'total': 3531}{'energy': 1631, 'idle': 1900, 'total': 3531}Passed
fee oracle 2{'energy': 290, 'idle': 0, 'total': 650}{'energy': 290, 'idle': 0, 'total': 500}Failed
fee oracle 3{'energy': 246, 'idle': 50, 'total': 300}{'energy': 246, 'idle': 50, 'total': 300}Passed
fee oracle 4{'energy': 149, 'idle': 100, 'total': 600}{'energy': 149, 'idle': 100, 'total': 500}Failed
fee oracle 5{'energy': 123, 'idle': 200, 'total': 650}{'energy': 123, 'idle': 200, 'total': 500}Failed
fee oracle 6{'energy': 1381, 'idle': 0, 'total': 1381}{'energy': 1381, 'idle': 0, 'total': 1381}Passed
fee oracle 7{'energy': 24, 'idle': 1000, 'total': 1024}{'energy': 24, 'idle': 1000, 'total': 1024}Passed

SHA-256 / 0d841b6449c768e265558ffce829e1cb9ce54ffa6ab5b3075054457a82a2cbc3

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    energy = -(-x['wh'] * x['price_per_kwh'] // 1000)
    idle = max(0, x['unplug'] - x['charge_end'] - x['idle_grace'])
    idle_fee = min(x['idle_cap'], -(-idle // 10) * x['idle_rate'])
    total = x['session_fee'] + energy + idle_fee
    return {'energy': energy, 'idle': idle_fee, 'total': max(x['min_fee'], energy) + x['session_fee'] + idle_fee}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 93, 'charge_end': 112, 'unplug': 312, 'wh': 46598, 'price_per_kwh': 35, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 0, 'min_fee': 500}, {'energy': 1631, 'idle': 1900, 'total': 3531}), ({'plug_in': 548, 'charge_end': 701, 'unplug': 706, 'wh': 9990, 'price_per_kwh': 29, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 500}, {'energy': 290, 'idle': 0, 'total': 500}), ({'plug_in': 502, 'charge_end': 683, 'unplug': 698, 'wh': 5462, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 50, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 300}, {'energy': 246, 'idle': 50, 'total': 300}), ({'plug_in': 119, 'charge_end': 199, 'unplug': 215, 'wh': 5114, 'price_per_kwh': 29, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 100, 'min_fee': 500}, {'energy': 149, 'idle': 100, 'total': 500}), ({'plug_in': 74, 'charge_end': 111, 'unplug': 171, 'wh': 4221, 'price_per_kwh': 29, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 500}, {'energy': 123, 'idle': 200, 'total': 500}), ({'plug_in': 585, 'charge_end': 800, 'unplug': 810, 'wh': 39441, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 2000, 'session_fee': 0, 'min_fee': 500}, {'energy': 1381, 'idle': 0, 'total': 1381}), ({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024})], [({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024}), ({'plug_in': 4, 'charge_end': 296, 'unplug': 312, 'wh': 3717, 'price_per_kwh': 52, 'idle_grace': 10, 'idle_rate': 40, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 500}, {'energy': 194, 'idle': 40, 'total': 500}), ({'plug_in': 73, 'charge_end': 83, 'unplug': 283, 'wh': 4230, 'price_per_kwh': 35, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 100, 'min_fee': 200}, {'energy': 149, 'idle': 1000, 'total': 1249}), ({'plug_in': 115, 'charge_end': 331, 'unplug': 346, 'wh': 4709, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 200}, {'energy': 245, 'idle': 0, 'total': 395}), ({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 490, 'charge_end': 569, 'unplug': 569, 'wh': 4974, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 100, 'min_fee': 300}, {'energy': 259, 'idle': 0, 'total': 359}), ({'plug_in': 157, 'charge_end': 214, 'unplug': 274, 'wh': 2276, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 50, 'idle_cap': 1000, 'session_fee': 150, 'min_fee': 500}, {'energy': 103, 'idle': 250, 'total': 503}), ({'plug_in': 230, 'charge_end': 290, 'unplug': 306, 'wh': 27281, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 300}, {'energy': 1228, 'idle': 100, 'total': 1478})], [({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 361, 'charge_end': 626, 'unplug': 626, 'wh': 29818, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 150, 'min_fee': 300}, {'energy': 1551, 'idle': 0, 'total': 1701}), ({'plug_in': 58, 'charge_end': 244, 'unplug': 260, 'wh': 4184, 'price_per_kwh': 45, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 100, 'min_fee': 300}, {'energy': 189, 'idle': 100, 'total': 389}), ({'plug_in': 34, 'charge_end': 215, 'unplug': 215, 'wh': 13150, 'price_per_kwh': 35, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 100, 'min_fee': 500}, {'energy': 461, 'idle': 0, 'total': 561}), ({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024}), ({'plug_in': 437, 'charge_end': 628, 'unplug': 628, 'wh': 6615, 'price_per_kwh': 45, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 298, 'idle': 0, 'total': 398}), ({'plug_in': 86, 'charge_end': 283, 'unplug': 288, 'wh': 13385, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 697, 'idle': 0, 'total': 697}), ({'plug_in': 433, 'charge_end': 493, 'unplug': 893, 'wh': 1131, 'price_per_kwh': 45, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 2000, 'session_fee': 0, 'min_fee': 200}, {'energy': 51, 'idle': 1560, 'total': 1611})], [({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024}), ({'plug_in': 63, 'charge_end': 346, 'unplug': 406, 'wh': 5005, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 500}, {'energy': 176, 'idle': 250, 'total': 576}), ({'plug_in': 197, 'charge_end': 253, 'unplug': 263, 'wh': 7897, 'price_per_kwh': 45, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 100, 'min_fee': 500}, {'energy': 356, 'idle': 0, 'total': 500}), ({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 484, 'charge_end': 672, 'unplug': 682, 'wh': 3159, 'price_per_kwh': 52, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 200}, {'energy': 165, 'idle': 0, 'total': 315}), ({'plug_in': 540, 'charge_end': 691, 'unplug': 691, 'wh': 40240, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 300}, {'energy': 1409, 'idle': 0, 'total': 1559}), ({'plug_in': 530, 'charge_end': 706, 'unplug': 722, 'wh': 19196, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 200}, {'energy': 557, 'idle': 100, 'total': 757}), ({'plug_in': 103, 'charge_end': 177, 'unplug': 377, 'wh': 8629, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 40, 'idle_cap': 3000, 'session_fee': 0, 'min_fee': 500}, {'energy': 389, 'idle': 760, 'total': 1149})], [({'plug_in': 537, 'charge_end': 679, 'unplug': 704, 'wh': 2203, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 64, 'idle': 200, 'total': 364}), ({'plug_in': 358, 'charge_end': 474, 'unplug': 484, 'wh': 14178, 'price_per_kwh': 29, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 2000, 'session_fee': 150, 'min_fee': 500}, {'energy': 412, 'idle': 0, 'total': 562}), ({'plug_in': 193, 'charge_end': 361, 'unplug': 386, 'wh': 58152, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 40, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 300}, {'energy': 3024, 'idle': 40, 'total': 3064}), ({'plug_in': 0, 'charge_end': 90, 'unplug': 106, 'wh': 12500, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 300}, {'energy': 438, 'idle': 50, 'total': 588}), ({'plug_in': 80, 'charge_end': 341, 'unplug': 346, 'wh': 6794, 'price_per_kwh': 35, 'idle_grace': 15, 'idle_rate': 100, 'idle_cap': 2000, 'session_fee': 100, 'min_fee': 500}, {'energy': 238, 'idle': 0, 'total': 500}), ({'plug_in': 473, 'charge_end': 503, 'unplug': 519, 'wh': 7069, 'price_per_kwh': 45, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 3000, 'session_fee': 0, 'min_fee': 500}, {'energy': 319, 'idle': 100, 'total': 500}), ({'plug_in': 30, 'charge_end': 45, 'unplug': 400, 'wh': 800, 'price_per_kwh': 29, 'idle_grace': 10, 'idle_rate': 100, 'idle_cap': 1000, 'session_fee': 0, 'min_fee': 500}, {'energy': 24, 'idle': 1000, 'total': 1024}), ({'plug_in': 411, 'charge_end': 481, 'unplug': 541, 'wh': 51535, 'price_per_kwh': 52, 'idle_grace': 15, 'idle_rate': 50, 'idle_cap': 3000, 'session_fee': 150, 'min_fee': 500}, {'energy': 2680, 'idle': 250, 'total': 3080})]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('fee oracle' + ' %d' % i, 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
fee oracle 0{'energy': 438, 'idle': 50, 'total': 588}{'energy': 438, 'idle': 50, 'total': 588}Passed
fee oracle 1{'energy': 1631, 'idle': 1900, 'total': 3531}{'energy': 1631, 'idle': 1900, 'total': 3531}Passed
fee oracle 2{'energy': 290, 'idle': 0, 'total': 650}{'energy': 290, 'idle': 0, 'total': 500}Failed
fee oracle 3{'energy': 246, 'idle': 50, 'total': 350}{'energy': 246, 'idle': 50, 'total': 300}Failed
fee oracle 4{'energy': 149, 'idle': 100, 'total': 700}{'energy': 149, 'idle': 100, 'total': 500}Failed
fee oracle 5{'energy': 123, 'idle': 200, 'total': 850}{'energy': 123, 'idle': 200, 'total': 500}Failed
fee oracle 6{'energy': 1381, 'idle': 0, 'total': 1381}{'energy': 1381, 'idle': 0, 'total': 1381}Passed
fee oracle 7{'energy': 24, 'idle': 1000, 'total': 1500}{'energy': 24, 'idle': 1000, 'total': 1024}Failed

SHA-256 / 8415f323688c07c78804c1b4a84dc57b00ad18d27cca03179b5319aba9006187

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 8 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

A deterministic, bounded toy model with a stipulated contract; it makes no claim of conformance to any agency manual or standard. 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 2026-09-29T14:48:04.838482+00:00.

Case digest / dce671fb935aaafa93417312d58e5714f1dc1452a4914f4b2266967213ad11db