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FA-85421 / Ride-hailing fare and surge pricing / Open access

Voided quote recomputed from the estimated distance · case 01

A rider who lengthened the trip pays for the estimated distance.

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

ROOT CAUSE

The meter recompute uses the quote estimate instead of actual meters.

VERIFIED REPAIR

Recompute from actual meters and seconds.

Unsuccessful approach: Using the estimated time instead of actual seconds still prices the old trip.

Case contract

An upfront quote is honored unless (checked in this order) the destination changed, stops were added, actual distance exceeds the estimate by more than 25% (m*4 > est*5), or actual time exceeds it by more than 50% (s*2 > est*3). Otherwise-recomputed fares use actual meters and seconds: base + half-up(m*per_km/1000) + half-up(s*per_min/60). Return the charge and the reason code.

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(quote, actual, rate):
    def metered():
        return rate['base'] + (quote['est_m'] * rate['per_km'] * 2 + 1000) // 2000 + (actual['s'] * rate['per_min'] * 2 + 60) // 120
    if actual['dest'] != quote['dest']:
        reason = 'destination'
    elif actual['stops_added'] > 0:
        reason = 'stops'
    elif actual['m'] * 4 > quote['est_m'] * 5:
        reason = 'distance'
    elif actual['s'] * 2 > quote['est_s'] * 3:
        reason = 'time'
    else:
        reason = 'quote'
    charged = quote['price'] if reason == 'quote' else metered()
    return {'charged': charged, 'reason': reason}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1385, 'reason': 'stops'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1261, 'reason': 'distance'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D2', 'm': 5000, 's': 900, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1125, 'reason': 'destination'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10001, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 10000, 's': 1801, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2501, 'reason': 'stops'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 6000, 's': 1350, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1738, 'reason': 'stops'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 10002, 's': 1100, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2092, 'reason': 'stops'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1701, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 905, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 10000, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 3800, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10002, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2151, 'reason': 'distance'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 10000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1851, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1002, 's': 1351, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 760, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 4000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 3800, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 5000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 802, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 667, 'reason': 'destination'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 5001, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1392, 'reason': 'destination'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 10001, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1900, 'reason': 'destination'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 9800, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 802, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 10002, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2850, 'reason': 'distance'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 902, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2064, 'reason': 'stops'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1578, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 8001, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 3800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'})]]
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: recompute inputs{'charged': 1165, 'reason': 'stops'}{'charged': 1385, 'reason': 'stops'}Failed
partial repair probe: recompute inputs{'charged': 1041, 'reason': 'distance'}{'charged': 1261, 'reason': 'distance'}Failed
second regression{'charged': 1000, 'reason': 'destination'}{'charged': 1125, 'reason': 'destination'}Failed
normal control 1{'charged': 2100, 'reason': 'quote'}{'charged': 2100, 'reason': 'quote'}Passed
normal control 2{'charged': 2501, 'reason': 'stops'}{'charged': 2501, 'reason': 'stops'}Passed
normal control 3{'charged': 2100, 'reason': 'quote'}{'charged': 2100, 'reason': 'quote'}Passed
normal control 4{'charged': 3999, 'reason': 'quote'}{'charged': 3999, 'reason': 'quote'}Passed

SHA-256 / 4a74e5874de2efa4974b1564c7b289e2fe42693907368a578bb9ca3e51f148c7

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(quote, actual, rate):
    def metered():
        return rate['base'] + (actual['m'] * rate['per_km'] * 2 + 1000) // 2000 + (quote['est_s'] * rate['per_min'] * 2 + 60) // 120
    if actual['dest'] != quote['dest']:
        reason = 'destination'
    elif actual['stops_added'] > 0:
        reason = 'stops'
    elif actual['m'] * 4 > quote['est_m'] * 5:
        reason = 'distance'
    elif actual['s'] * 2 > quote['est_s'] * 3:
        reason = 'time'
    else:
        reason = 'quote'
    charged = quote['price'] if reason == 'quote' else metered()
    return {'charged': charged, 'reason': reason}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1385, 'reason': 'stops'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1261, 'reason': 'distance'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D2', 'm': 5000, 's': 900, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1125, 'reason': 'destination'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10001, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 10000, 's': 1801, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2501, 'reason': 'stops'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 6000, 's': 1350, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1738, 'reason': 'stops'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 10002, 's': 1100, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2092, 'reason': 'stops'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1701, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 905, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 10000, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 3800, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10002, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2151, 'reason': 'distance'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 10000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1851, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1002, 's': 1351, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 760, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 4000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 3800, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 5000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 802, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 667, 'reason': 'destination'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 5001, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1392, 'reason': 'destination'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 10001, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1900, 'reason': 'destination'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 9800, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 802, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 10002, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2850, 'reason': 'distance'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 902, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2064, 'reason': 'stops'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1578, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 8001, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 3800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'})]]
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: recompute inputs{'charged': 1385, 'reason': 'stops'}{'charged': 1385, 'reason': 'stops'}Passed
partial repair probe: recompute inputs{'charged': 1060, 'reason': 'distance'}{'charged': 1261, 'reason': 'distance'}Failed
second regression{'charged': 1125, 'reason': 'destination'}{'charged': 1125, 'reason': 'destination'}Passed
normal control 1{'charged': 2100, 'reason': 'quote'}{'charged': 2100, 'reason': 'quote'}Passed
normal control 2{'charged': 2501, 'reason': 'stops'}{'charged': 2501, 'reason': 'stops'}Passed
normal control 3{'charged': 2100, 'reason': 'quote'}{'charged': 2100, 'reason': 'quote'}Passed
normal control 4{'charged': 3999, 'reason': 'quote'}{'charged': 3999, 'reason': 'quote'}Passed

SHA-256 / e2ab2ce759f7e28c5dfa763e0c37c3647aec795a17b52e40b0b96a566cb954e3

3 / The verified repair

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

N = 1
observations = []
def solve(quote, actual, rate):
    def metered():
        return rate['base'] + (actual['m'] * rate['per_km'] * 2 + 1000) // 2000 + (actual['s'] * rate['per_min'] * 2 + 60) // 120
    if actual['dest'] != quote['dest']:
        reason = 'destination'
    elif actual['stops_added'] > 0:
        reason = 'stops'
    elif actual['m'] * 4 > quote['est_m'] * 5:
        reason = 'distance'
    elif actual['s'] * 2 > quote['est_s'] * 3:
        reason = 'time'
    else:
        reason = 'quote'
    charged = quote['price'] if reason == 'quote' else metered()
    return {'charged': charged, 'reason': reason}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1385, 'reason': 'stops'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1261, 'reason': 'distance'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D2', 'm': 5000, 's': 900, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1125, 'reason': 'destination'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10001, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 10000, 's': 1801, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2501, 'reason': 'stops'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 6000, 's': 1350, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1738, 'reason': 'stops'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 10002, 's': 1100, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2092, 'reason': 'stops'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1701, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 905, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 10000, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 3800, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10002, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2151, 'reason': 'distance'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 10000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1851, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1002, 's': 1351, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 760, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 4000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 3800, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 5000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 802, 's': 1100, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 667, 'reason': 'destination'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 5001, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1392, 'reason': 'destination'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 10001, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1900, 'reason': 'destination'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 9800, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 802, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: recompute inputs',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 10002, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2850, 'reason': 'distance'}),
  ('partial repair probe: recompute inputs',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 902, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2064, 'reason': 'stops'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 9800, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1578, 'reason': 'stops'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 8001, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 3800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'})]]
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: recompute inputs{'charged': 1385, 'reason': 'stops'}{'charged': 1385, 'reason': 'stops'}Passed
partial repair probe: recompute inputs{'charged': 1261, 'reason': 'distance'}{'charged': 1261, 'reason': 'distance'}Passed
second regression{'charged': 1125, 'reason': 'destination'}{'charged': 1125, 'reason': 'destination'}Passed
normal control 1{'charged': 2100, 'reason': 'quote'}{'charged': 2100, 'reason': 'quote'}Passed
normal control 2{'charged': 2501, 'reason': 'stops'}{'charged': 2501, 'reason': 'stops'}Passed
normal control 3{'charged': 2100, 'reason': 'quote'}{'charged': 2100, 'reason': 'quote'}Passed
normal control 4{'charged': 3999, 'reason': 'quote'}{'charged': 3999, 'reason': 'quote'}Passed

SHA-256 / 7eacd7f17336ab47ac7a7e6e27bd5b566fd9716a80ebaa98df4098efbce5a419

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 2026-09-29T14:50:40.274295+00:00.

Case digest / e704d3efd46729452bdec5ec3bdd92006a9ba09630714615105f444ea392cf82