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FA-85356 / Ride-hailing fare and surge pricing / Open access

Base fare added on top of the minimum · case 01

A minimum-fare trip is charged the minimum plus the base fare.

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

ROOT CAUSE

The base fare is excluded from the subtotal compared with the minimum and added afterwards.

VERIFIED REPAIR

Include the base fare in the subtotal compared with the minimum.

Unsuccessful approach: Raising the minimum by the base fare charges the same inflated floor.

Case contract

All money is integer cents. Distance charge = meters x per_km / 1000 and time charge = seconds x per_min / 60, each rounded half up to a cent on its own. Subtotal = base + distance + time. The minimum fare applies to that subtotal only; the booking fee is added after the minimum. Return the distance charge, time charge and fare.

Why this case matters

Ride-hailing prices are computed per trip at scale; ordering, unit and boundary slips become systematic over- or under-charging.

1 / The failure

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

N = 1
observations = []
def solve(trip, rate):
    def half_up(num, den):
        return (num * 2 + den) // (den * 2)
    dist = half_up(trip['meters'] * rate['per_km'], 1000)
    tm = half_up(trip['seconds'] * rate['per_min'], 60)
    sub = dist + tm
    fare = max(sub, rate['minimum']) + rate['base'] + rate['booking_fee']
    return {'distance': dist, 'time': tm, 'fare': fare}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: base inside minimum',
   [{'meters': 4, 'seconds': 1629},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 95, 'per_min': 25}],
   {'distance': 0, 'fare': 1250, 'time': 679}),
  ('partial repair probe: base inside minimum',
   [{'meters': 2500, 'seconds': 0},
    {'base': 150, 'booking_fee': 250, 'minimum': 700, 'per_km': 95, 'per_min': 30}],
   {'distance': 238, 'fare': 950, 'time': 0}),
  ('second regression',
   [{'meters': 0, 'seconds': 61},
    {'base': 150, 'booking_fee': 250, 'minimum': 500, 'per_km': 250, 'per_min': 35}],
   {'distance': 0, 'fare': 750, 'time': 36}),
  ('normal control 1',
   [{'meters': 14115, 'seconds': 90},
    {'base': 250, 'booking_fee': 0, 'minimum': 1000, 'per_km': 125, 'per_min': 30}],
   {'distance': 1764, 'fare': 2059, 'time': 45}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 121},
    {'base': 0, 'booking_fee': 0, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 125, 'fare': 700, 'time': 71}),
  ('normal control 3',
   [{'meters': 0, 'seconds': 61},
    {'base': 0, 'booking_fee': 0, 'minimum': 1000, 'per_km': 250, 'per_min': 35}],
   {'distance': 0, 'fare': 1000, 'time': 36}),
  ('normal control 4',
   [{'meters': 6825, 'seconds': 61},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 250, 'per_min': 30}],
   {'distance': 1706, 'fare': 2237, 'time': 31})],
 [('regression: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 35}],
   {'distance': 0, 'fare': 750, 'time': 36}),
  ('partial repair probe: base inside minimum',
   [{'meters': 0, 'seconds': 61},
    {'base': 150, 'booking_fee': 175, 'minimum': 1000, 'per_km': 110, 'per_min': 35}],
   {'distance': 0, 'fare': 1175, 'time': 36}),
  ('second regression',
   [{'meters': 4, 'seconds': 0},
    {'base': 150, 'booking_fee': 250, 'minimum': 700, 'per_km': 125, 'per_min': 35}],
   {'distance': 1, 'fare': 950, 'time': 0}),
  ('normal control 1',
   [{'meters': 21815, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 1000, 'per_km': 125, 'per_min': 25}],
   {'distance': 2727, 'fare': 3002, 'time': 25}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 0},
    {'base': 0, 'booking_fee': 0, 'minimum': 500, 'per_km': 250, 'per_min': 25}],
   {'distance': 125, 'fare': 500, 'time': 0}),
  ('normal control 3',
   [{'meters': 0, 'seconds': 90},
    {'base': 0, 'booking_fee': 250, 'minimum': 500, 'per_km': 110, 'per_min': 30}],
   {'distance': 0, 'fare': 750, 'time': 45}),
  ('normal control 4',
   [{'meters': 12, 'seconds': 90},
    {'base': 0, 'booking_fee': 175, 'minimum': 700, 'per_km': 250, 'per_min': 30}],
   {'distance': 3, 'fare': 875, 'time': 45})],
 [('regression: base inside minimum',
   [{'meters': 0, 'seconds': 90},
    {'base': 150, 'booking_fee': 250, 'minimum': 500, 'per_km': 110, 'per_min': 25}],
   {'distance': 0, 'fare': 750, 'time': 38}),
  ('partial repair probe: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 700, 'per_km': 110, 'per_min': 30}],
   {'distance': 0, 'fare': 700, 'time': 31}),
  ('second regression',
   [{'meters': 12, 'seconds': 214},
    {'base': 250, 'booking_fee': 175, 'minimum': 700, 'per_km': 95, 'per_min': 25}],
   {'distance': 1, 'fare': 875, 'time': 89}),
  ('normal control 1',
   [{'meters': 0, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 110, 'per_min': 15}],
   {'distance': 0, 'fare': 950, 'time': 8}),
  ('normal control 2',
   [{'meters': 11380, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 2845, 'fare': 3113, 'time': 18}),
  ('normal control 3',
   [{'meters': 14883, 'seconds': 245},
    {'base': 150, 'booking_fee': 175, 'minimum': 500, 'per_km': 125, 'per_min': 30}],
   {'distance': 1860, 'fare': 2308, 'time': 123}),
  ('normal control 4',
   [{'meters': 17188, 'seconds': 0},
    {'base': 250, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 35}],
   {'distance': 1633, 'fare': 2133, 'time': 0})],
 [('regression: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 175, 'minimum': 1000, 'per_km': 95, 'per_min': 30}],
   {'distance': 0, 'fare': 1175, 'time': 31}),
  ('partial repair probe: base inside minimum',
   [{'meters': 0, 'seconds': 30},
    {'base': 250, 'booking_fee': 250, 'minimum': 700, 'per_km': 95, 'per_min': 25}],
   {'distance': 0, 'fare': 950, 'time': 13}),
  ('second regression',
   [{'meters': 1004, 'seconds': 90},
    {'base': 150, 'booking_fee': 0, 'minimum': 500, 'per_km': 110, 'per_min': 25}],
   {'distance': 110, 'fare': 500, 'time': 38}),
  ('normal control 1',
   [{'meters': 500, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 125, 'per_min': 15}],
   {'distance': 63, 'fare': 950, 'time': 8}),
  ('normal control 2',
   [{'meters': 12, 'seconds': 0}, {'base': 0, 'booking_fee': 0, 'minimum': 700, 'per_km': 95, 'per_min': 15}],
   {'distance': 1, 'fare': 700, 'time': 0}),
  ('normal control 3',
   [{'meters': 4, 'seconds': 0},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 1, 'fare': 950, 'time': 0}),
  ('normal control 4',
   [{'meters': 2500, 'seconds': 0},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 625, 'fare': 950, 'time': 0})],
 [('regression: base inside minimum',
   [{'meters': 500, 'seconds': 30},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 110, 'per_min': 30}],
   {'distance': 55, 'fare': 1250, 'time': 15}),
  ('partial repair probe: base inside minimum',
   [{'meters': 2500, 'seconds': 30},
    {'base': 250, 'booking_fee': 0, 'minimum': 500, 'per_km': 125, 'per_min': 25}],
   {'distance': 313, 'fare': 576, 'time': 13}),
  ('second regression',
   [{'meters': 500, 'seconds': 61},
    {'base': 250, 'booking_fee': 175, 'minimum': 700, 'per_km': 250, 'per_min': 15}],
   {'distance': 125, 'fare': 875, 'time': 15}),
  ('normal control 1',
   [{'meters': 500, 'seconds': 1622},
    {'base': 250, 'booking_fee': 175, 'minimum': 500, 'per_km': 250, 'per_min': 15}],
   {'distance': 125, 'fare': 956, 'time': 406}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 90},
    {'base': 0, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 15}],
   {'distance': 48, 'fare': 750, 'time': 23}),
  ('normal control 3',
   [{'meters': 15947, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 700, 'per_km': 125, 'per_min': 15}],
   {'distance': 1993, 'fare': 2258, 'time': 15}),
  ('normal control 4',
   [{'meters': 2500, 'seconds': 2303},
    {'base': 150, 'booking_fee': 250, 'minimum': 1000, 'per_km': 125, 'per_min': 25}],
   {'distance': 313, 'fare': 1673, 'time': 960})]]
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: base inside minimum{'distance': 0, 'fare': 1500, 'time': 679}{'distance': 0, 'fare': 1250, 'time': 679}Failed
partial repair probe: base inside minimum{'distance': 238, 'fare': 1100, 'time': 0}{'distance': 238, 'fare': 950, 'time': 0}Failed
second regression{'distance': 0, 'fare': 900, 'time': 36}{'distance': 0, 'fare': 750, 'time': 36}Failed
normal control 1{'distance': 1764, 'fare': 2059, 'time': 45}{'distance': 1764, 'fare': 2059, 'time': 45}Passed
normal control 2{'distance': 125, 'fare': 700, 'time': 71}{'distance': 125, 'fare': 700, 'time': 71}Passed
normal control 3{'distance': 0, 'fare': 1000, 'time': 36}{'distance': 0, 'fare': 1000, 'time': 36}Passed
normal control 4{'distance': 1706, 'fare': 2237, 'time': 31}{'distance': 1706, 'fare': 2237, 'time': 31}Passed

SHA-256 / 8037704722afe759c656edd107e46f972fc3a890a8e8e9eceba92a5ccedcb1db

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(trip, rate):
    def half_up(num, den):
        return (num * 2 + den) // (den * 2)
    dist = half_up(trip['meters'] * rate['per_km'], 1000)
    tm = half_up(trip['seconds'] * rate['per_min'], 60)
    sub = rate['base'] + dist + tm
    fare = max(sub, rate['minimum'] + rate['base']) + rate['booking_fee']
    return {'distance': dist, 'time': tm, 'fare': fare}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: base inside minimum',
   [{'meters': 4, 'seconds': 1629},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 95, 'per_min': 25}],
   {'distance': 0, 'fare': 1250, 'time': 679}),
  ('partial repair probe: base inside minimum',
   [{'meters': 2500, 'seconds': 0},
    {'base': 150, 'booking_fee': 250, 'minimum': 700, 'per_km': 95, 'per_min': 30}],
   {'distance': 238, 'fare': 950, 'time': 0}),
  ('second regression',
   [{'meters': 0, 'seconds': 61},
    {'base': 150, 'booking_fee': 250, 'minimum': 500, 'per_km': 250, 'per_min': 35}],
   {'distance': 0, 'fare': 750, 'time': 36}),
  ('normal control 1',
   [{'meters': 14115, 'seconds': 90},
    {'base': 250, 'booking_fee': 0, 'minimum': 1000, 'per_km': 125, 'per_min': 30}],
   {'distance': 1764, 'fare': 2059, 'time': 45}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 121},
    {'base': 0, 'booking_fee': 0, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 125, 'fare': 700, 'time': 71}),
  ('normal control 3',
   [{'meters': 0, 'seconds': 61},
    {'base': 0, 'booking_fee': 0, 'minimum': 1000, 'per_km': 250, 'per_min': 35}],
   {'distance': 0, 'fare': 1000, 'time': 36}),
  ('normal control 4',
   [{'meters': 6825, 'seconds': 61},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 250, 'per_min': 30}],
   {'distance': 1706, 'fare': 2237, 'time': 31})],
 [('regression: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 35}],
   {'distance': 0, 'fare': 750, 'time': 36}),
  ('partial repair probe: base inside minimum',
   [{'meters': 0, 'seconds': 61},
    {'base': 150, 'booking_fee': 175, 'minimum': 1000, 'per_km': 110, 'per_min': 35}],
   {'distance': 0, 'fare': 1175, 'time': 36}),
  ('second regression',
   [{'meters': 4, 'seconds': 0},
    {'base': 150, 'booking_fee': 250, 'minimum': 700, 'per_km': 125, 'per_min': 35}],
   {'distance': 1, 'fare': 950, 'time': 0}),
  ('normal control 1',
   [{'meters': 21815, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 1000, 'per_km': 125, 'per_min': 25}],
   {'distance': 2727, 'fare': 3002, 'time': 25}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 0},
    {'base': 0, 'booking_fee': 0, 'minimum': 500, 'per_km': 250, 'per_min': 25}],
   {'distance': 125, 'fare': 500, 'time': 0}),
  ('normal control 3',
   [{'meters': 0, 'seconds': 90},
    {'base': 0, 'booking_fee': 250, 'minimum': 500, 'per_km': 110, 'per_min': 30}],
   {'distance': 0, 'fare': 750, 'time': 45}),
  ('normal control 4',
   [{'meters': 12, 'seconds': 90},
    {'base': 0, 'booking_fee': 175, 'minimum': 700, 'per_km': 250, 'per_min': 30}],
   {'distance': 3, 'fare': 875, 'time': 45})],
 [('regression: base inside minimum',
   [{'meters': 0, 'seconds': 90},
    {'base': 150, 'booking_fee': 250, 'minimum': 500, 'per_km': 110, 'per_min': 25}],
   {'distance': 0, 'fare': 750, 'time': 38}),
  ('partial repair probe: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 700, 'per_km': 110, 'per_min': 30}],
   {'distance': 0, 'fare': 700, 'time': 31}),
  ('second regression',
   [{'meters': 12, 'seconds': 214},
    {'base': 250, 'booking_fee': 175, 'minimum': 700, 'per_km': 95, 'per_min': 25}],
   {'distance': 1, 'fare': 875, 'time': 89}),
  ('normal control 1',
   [{'meters': 0, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 110, 'per_min': 15}],
   {'distance': 0, 'fare': 950, 'time': 8}),
  ('normal control 2',
   [{'meters': 11380, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 2845, 'fare': 3113, 'time': 18}),
  ('normal control 3',
   [{'meters': 14883, 'seconds': 245},
    {'base': 150, 'booking_fee': 175, 'minimum': 500, 'per_km': 125, 'per_min': 30}],
   {'distance': 1860, 'fare': 2308, 'time': 123}),
  ('normal control 4',
   [{'meters': 17188, 'seconds': 0},
    {'base': 250, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 35}],
   {'distance': 1633, 'fare': 2133, 'time': 0})],
 [('regression: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 175, 'minimum': 1000, 'per_km': 95, 'per_min': 30}],
   {'distance': 0, 'fare': 1175, 'time': 31}),
  ('partial repair probe: base inside minimum',
   [{'meters': 0, 'seconds': 30},
    {'base': 250, 'booking_fee': 250, 'minimum': 700, 'per_km': 95, 'per_min': 25}],
   {'distance': 0, 'fare': 950, 'time': 13}),
  ('second regression',
   [{'meters': 1004, 'seconds': 90},
    {'base': 150, 'booking_fee': 0, 'minimum': 500, 'per_km': 110, 'per_min': 25}],
   {'distance': 110, 'fare': 500, 'time': 38}),
  ('normal control 1',
   [{'meters': 500, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 125, 'per_min': 15}],
   {'distance': 63, 'fare': 950, 'time': 8}),
  ('normal control 2',
   [{'meters': 12, 'seconds': 0}, {'base': 0, 'booking_fee': 0, 'minimum': 700, 'per_km': 95, 'per_min': 15}],
   {'distance': 1, 'fare': 700, 'time': 0}),
  ('normal control 3',
   [{'meters': 4, 'seconds': 0},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 1, 'fare': 950, 'time': 0}),
  ('normal control 4',
   [{'meters': 2500, 'seconds': 0},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 625, 'fare': 950, 'time': 0})],
 [('regression: base inside minimum',
   [{'meters': 500, 'seconds': 30},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 110, 'per_min': 30}],
   {'distance': 55, 'fare': 1250, 'time': 15}),
  ('partial repair probe: base inside minimum',
   [{'meters': 2500, 'seconds': 30},
    {'base': 250, 'booking_fee': 0, 'minimum': 500, 'per_km': 125, 'per_min': 25}],
   {'distance': 313, 'fare': 576, 'time': 13}),
  ('second regression',
   [{'meters': 500, 'seconds': 61},
    {'base': 250, 'booking_fee': 175, 'minimum': 700, 'per_km': 250, 'per_min': 15}],
   {'distance': 125, 'fare': 875, 'time': 15}),
  ('normal control 1',
   [{'meters': 500, 'seconds': 1622},
    {'base': 250, 'booking_fee': 175, 'minimum': 500, 'per_km': 250, 'per_min': 15}],
   {'distance': 125, 'fare': 956, 'time': 406}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 90},
    {'base': 0, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 15}],
   {'distance': 48, 'fare': 750, 'time': 23}),
  ('normal control 3',
   [{'meters': 15947, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 700, 'per_km': 125, 'per_min': 15}],
   {'distance': 1993, 'fare': 2258, 'time': 15}),
  ('normal control 4',
   [{'meters': 2500, 'seconds': 2303},
    {'base': 150, 'booking_fee': 250, 'minimum': 1000, 'per_km': 125, 'per_min': 25}],
   {'distance': 313, 'fare': 1673, 'time': 960})]]
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: base inside minimum{'distance': 0, 'fare': 1500, 'time': 679}{'distance': 0, 'fare': 1250, 'time': 679}Failed
partial repair probe: base inside minimum{'distance': 238, 'fare': 1100, 'time': 0}{'distance': 238, 'fare': 950, 'time': 0}Failed
second regression{'distance': 0, 'fare': 900, 'time': 36}{'distance': 0, 'fare': 750, 'time': 36}Failed
normal control 1{'distance': 1764, 'fare': 2059, 'time': 45}{'distance': 1764, 'fare': 2059, 'time': 45}Passed
normal control 2{'distance': 125, 'fare': 700, 'time': 71}{'distance': 125, 'fare': 700, 'time': 71}Passed
normal control 3{'distance': 0, 'fare': 1000, 'time': 36}{'distance': 0, 'fare': 1000, 'time': 36}Passed
normal control 4{'distance': 1706, 'fare': 2237, 'time': 31}{'distance': 1706, 'fare': 2237, 'time': 31}Passed

SHA-256 / 6a441771108d7671295a8f0db02d56c45757d60eb6caa1009770aa25395dad1e

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(trip, rate):
    def half_up(num, den):
        return (num * 2 + den) // (den * 2)
    dist = half_up(trip['meters'] * rate['per_km'], 1000)
    tm = half_up(trip['seconds'] * rate['per_min'], 60)
    sub = rate['base'] + dist + tm
    fare = max(sub, rate['minimum']) + rate['booking_fee']
    return {'distance': dist, 'time': tm, 'fare': fare}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: base inside minimum',
   [{'meters': 4, 'seconds': 1629},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 95, 'per_min': 25}],
   {'distance': 0, 'fare': 1250, 'time': 679}),
  ('partial repair probe: base inside minimum',
   [{'meters': 2500, 'seconds': 0},
    {'base': 150, 'booking_fee': 250, 'minimum': 700, 'per_km': 95, 'per_min': 30}],
   {'distance': 238, 'fare': 950, 'time': 0}),
  ('second regression',
   [{'meters': 0, 'seconds': 61},
    {'base': 150, 'booking_fee': 250, 'minimum': 500, 'per_km': 250, 'per_min': 35}],
   {'distance': 0, 'fare': 750, 'time': 36}),
  ('normal control 1',
   [{'meters': 14115, 'seconds': 90},
    {'base': 250, 'booking_fee': 0, 'minimum': 1000, 'per_km': 125, 'per_min': 30}],
   {'distance': 1764, 'fare': 2059, 'time': 45}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 121},
    {'base': 0, 'booking_fee': 0, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 125, 'fare': 700, 'time': 71}),
  ('normal control 3',
   [{'meters': 0, 'seconds': 61},
    {'base': 0, 'booking_fee': 0, 'minimum': 1000, 'per_km': 250, 'per_min': 35}],
   {'distance': 0, 'fare': 1000, 'time': 36}),
  ('normal control 4',
   [{'meters': 6825, 'seconds': 61},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 250, 'per_min': 30}],
   {'distance': 1706, 'fare': 2237, 'time': 31})],
 [('regression: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 35}],
   {'distance': 0, 'fare': 750, 'time': 36}),
  ('partial repair probe: base inside minimum',
   [{'meters': 0, 'seconds': 61},
    {'base': 150, 'booking_fee': 175, 'minimum': 1000, 'per_km': 110, 'per_min': 35}],
   {'distance': 0, 'fare': 1175, 'time': 36}),
  ('second regression',
   [{'meters': 4, 'seconds': 0},
    {'base': 150, 'booking_fee': 250, 'minimum': 700, 'per_km': 125, 'per_min': 35}],
   {'distance': 1, 'fare': 950, 'time': 0}),
  ('normal control 1',
   [{'meters': 21815, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 1000, 'per_km': 125, 'per_min': 25}],
   {'distance': 2727, 'fare': 3002, 'time': 25}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 0},
    {'base': 0, 'booking_fee': 0, 'minimum': 500, 'per_km': 250, 'per_min': 25}],
   {'distance': 125, 'fare': 500, 'time': 0}),
  ('normal control 3',
   [{'meters': 0, 'seconds': 90},
    {'base': 0, 'booking_fee': 250, 'minimum': 500, 'per_km': 110, 'per_min': 30}],
   {'distance': 0, 'fare': 750, 'time': 45}),
  ('normal control 4',
   [{'meters': 12, 'seconds': 90},
    {'base': 0, 'booking_fee': 175, 'minimum': 700, 'per_km': 250, 'per_min': 30}],
   {'distance': 3, 'fare': 875, 'time': 45})],
 [('regression: base inside minimum',
   [{'meters': 0, 'seconds': 90},
    {'base': 150, 'booking_fee': 250, 'minimum': 500, 'per_km': 110, 'per_min': 25}],
   {'distance': 0, 'fare': 750, 'time': 38}),
  ('partial repair probe: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 700, 'per_km': 110, 'per_min': 30}],
   {'distance': 0, 'fare': 700, 'time': 31}),
  ('second regression',
   [{'meters': 12, 'seconds': 214},
    {'base': 250, 'booking_fee': 175, 'minimum': 700, 'per_km': 95, 'per_min': 25}],
   {'distance': 1, 'fare': 875, 'time': 89}),
  ('normal control 1',
   [{'meters': 0, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 110, 'per_min': 15}],
   {'distance': 0, 'fare': 950, 'time': 8}),
  ('normal control 2',
   [{'meters': 11380, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 2845, 'fare': 3113, 'time': 18}),
  ('normal control 3',
   [{'meters': 14883, 'seconds': 245},
    {'base': 150, 'booking_fee': 175, 'minimum': 500, 'per_km': 125, 'per_min': 30}],
   {'distance': 1860, 'fare': 2308, 'time': 123}),
  ('normal control 4',
   [{'meters': 17188, 'seconds': 0},
    {'base': 250, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 35}],
   {'distance': 1633, 'fare': 2133, 'time': 0})],
 [('regression: base inside minimum',
   [{'meters': 4, 'seconds': 61},
    {'base': 250, 'booking_fee': 175, 'minimum': 1000, 'per_km': 95, 'per_min': 30}],
   {'distance': 0, 'fare': 1175, 'time': 31}),
  ('partial repair probe: base inside minimum',
   [{'meters': 0, 'seconds': 30},
    {'base': 250, 'booking_fee': 250, 'minimum': 700, 'per_km': 95, 'per_min': 25}],
   {'distance': 0, 'fare': 950, 'time': 13}),
  ('second regression',
   [{'meters': 1004, 'seconds': 90},
    {'base': 150, 'booking_fee': 0, 'minimum': 500, 'per_km': 110, 'per_min': 25}],
   {'distance': 110, 'fare': 500, 'time': 38}),
  ('normal control 1',
   [{'meters': 500, 'seconds': 30},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 125, 'per_min': 15}],
   {'distance': 63, 'fare': 950, 'time': 8}),
  ('normal control 2',
   [{'meters': 12, 'seconds': 0}, {'base': 0, 'booking_fee': 0, 'minimum': 700, 'per_km': 95, 'per_min': 15}],
   {'distance': 1, 'fare': 700, 'time': 0}),
  ('normal control 3',
   [{'meters': 4, 'seconds': 0},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 1, 'fare': 950, 'time': 0}),
  ('normal control 4',
   [{'meters': 2500, 'seconds': 0},
    {'base': 0, 'booking_fee': 250, 'minimum': 700, 'per_km': 250, 'per_min': 35}],
   {'distance': 625, 'fare': 950, 'time': 0})],
 [('regression: base inside minimum',
   [{'meters': 500, 'seconds': 30},
    {'base': 250, 'booking_fee': 250, 'minimum': 1000, 'per_km': 110, 'per_min': 30}],
   {'distance': 55, 'fare': 1250, 'time': 15}),
  ('partial repair probe: base inside minimum',
   [{'meters': 2500, 'seconds': 30},
    {'base': 250, 'booking_fee': 0, 'minimum': 500, 'per_km': 125, 'per_min': 25}],
   {'distance': 313, 'fare': 576, 'time': 13}),
  ('second regression',
   [{'meters': 500, 'seconds': 61},
    {'base': 250, 'booking_fee': 175, 'minimum': 700, 'per_km': 250, 'per_min': 15}],
   {'distance': 125, 'fare': 875, 'time': 15}),
  ('normal control 1',
   [{'meters': 500, 'seconds': 1622},
    {'base': 250, 'booking_fee': 175, 'minimum': 500, 'per_km': 250, 'per_min': 15}],
   {'distance': 125, 'fare': 956, 'time': 406}),
  ('normal control 2',
   [{'meters': 500, 'seconds': 90},
    {'base': 0, 'booking_fee': 250, 'minimum': 500, 'per_km': 95, 'per_min': 15}],
   {'distance': 48, 'fare': 750, 'time': 23}),
  ('normal control 3',
   [{'meters': 15947, 'seconds': 61},
    {'base': 250, 'booking_fee': 0, 'minimum': 700, 'per_km': 125, 'per_min': 15}],
   {'distance': 1993, 'fare': 2258, 'time': 15}),
  ('normal control 4',
   [{'meters': 2500, 'seconds': 2303},
    {'base': 150, 'booking_fee': 250, 'minimum': 1000, 'per_km': 125, 'per_min': 25}],
   {'distance': 313, 'fare': 1673, 'time': 960})]]
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: base inside minimum{'distance': 0, 'fare': 1250, 'time': 679}{'distance': 0, 'fare': 1250, 'time': 679}Passed
partial repair probe: base inside minimum{'distance': 238, 'fare': 950, 'time': 0}{'distance': 238, 'fare': 950, 'time': 0}Passed
second regression{'distance': 0, 'fare': 750, 'time': 36}{'distance': 0, 'fare': 750, 'time': 36}Passed
normal control 1{'distance': 1764, 'fare': 2059, 'time': 45}{'distance': 1764, 'fare': 2059, 'time': 45}Passed
normal control 2{'distance': 125, 'fare': 700, 'time': 71}{'distance': 125, 'fare': 700, 'time': 71}Passed
normal control 3{'distance': 0, 'fare': 1000, 'time': 36}{'distance': 0, 'fare': 1000, 'time': 36}Passed
normal control 4{'distance': 1706, 'fare': 2237, 'time': 31}{'distance': 1706, 'fare': 2237, 'time': 31}Passed

SHA-256 / 20188a446cf404cfea6b60744a2203656a9bfed8db7cc895c63e88ffd6cf3dcb

Verification & scope

A deterministic toy pricing contract stipulated for this example; it does not reproduce the pricing of any real ride-hailing operator or regulator. 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 2026-09-29T14:50:39.640673+00:00.

Case digest / 0318453116681593195f1dd3b60e7d241f00daf65a4efa275f9a344c975834dc