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FA-85411 / Ride-hailing fare and surge pricing / Open access

Time tolerance ratio inverted · case 01

Any trip taking more than two thirds of the estimated time is metered.

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

ROOT CAUSE

The 1.5 tolerance is written as 3/2 on the wrong side, becoming 2/3.

VERIFIED REPAIR

Compare actual*2 against estimate*3.

Unsuccessful approach: Also requiring a longer route ignores delays on the planned route.

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'] + (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'] * 3 > quote['est_s'] * 2:
        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: time deviation ratio',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 5000, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1501, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 8001, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 1351, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1145, 'reason': 'time'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 5001, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1801, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D2', 'm': 8001, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1551, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 5000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 992, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 1002, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1710, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 4000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1041, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2813, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 10000, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2850, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1253, 's': 1351, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 807, 'reason': 'stops'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 10000, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2088, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 7801, 's': 902, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1584, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 4000, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1841, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D2', 'm': 5000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1125, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D2', 'm': 3800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1026, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 12001, 's': 601, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1720, 'reason': 'stops'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 12500, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'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': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1240, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 1503, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1165, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D2', 'm': 10000, 's': 900, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1975, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 10002, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2876, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 1503, 's': 1202, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1089, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 4000, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 9800, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2678, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 1002, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 739, 'reason': 'time'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 12001, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2721, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1389, 'reason': 'time'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 1253, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 938, 'reason': 'distance'})]]
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: time deviation ratio{'charged': 1017, 'reason': 'time'}{'charged': 1250, 'reason': 'quote'}Failed
partial repair probe: time deviation ratio{'charged': 1501, 'reason': 'time'}{'charged': 1501, 'reason': 'time'}Passed
second regression{'charged': 2776, 'reason': 'time'}{'charged': 2100, 'reason': 'quote'}Failed
normal control 1{'charged': 1145, 'reason': 'time'}{'charged': 1145, 'reason': 'time'}Passed
normal control 2{'charged': 1801, 'reason': 'distance'}{'charged': 1801, 'reason': 'distance'}Passed
normal control 3{'charged': 1551, 'reason': 'destination'}{'charged': 1551, 'reason': 'destination'}Passed
normal control 4{'charged': 992, 'reason': 'destination'}{'charged': 992, 'reason': 'destination'}Passed

SHA-256 / de5db6cac9e1762af63d7297048dc61246809aaf1d7b22effa209002c9e23e1e

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 + (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 and actual['m'] > quote['est_m']:
        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: time deviation ratio',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 5000, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1501, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 8001, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 1351, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1145, 'reason': 'time'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 5001, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1801, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D2', 'm': 8001, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1551, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 5000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 992, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 1002, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1710, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 4000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1041, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2813, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 10000, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2850, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1253, 's': 1351, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 807, 'reason': 'stops'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 10000, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2088, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 7801, 's': 902, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1584, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 4000, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1841, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D2', 'm': 5000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1125, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D2', 'm': 3800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1026, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 12001, 's': 601, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1720, 'reason': 'stops'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 12500, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'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': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1240, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 1503, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1165, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D2', 'm': 10000, 's': 900, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1975, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 10002, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2876, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 1503, 's': 1202, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1089, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 4000, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 9800, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2678, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 1002, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 739, 'reason': 'time'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 12001, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2721, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1389, 'reason': 'time'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 1253, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 938, 'reason': 'distance'})]]
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: time deviation ratio{'charged': 1250, 'reason': 'quote'}{'charged': 1250, 'reason': 'quote'}Passed
partial repair probe: time deviation ratio{'charged': 3999, 'reason': 'quote'}{'charged': 1501, 'reason': 'time'}Failed
second regression{'charged': 2100, 'reason': 'quote'}{'charged': 2100, 'reason': 'quote'}Passed
normal control 1{'charged': 1145, 'reason': 'time'}{'charged': 1145, 'reason': 'time'}Passed
normal control 2{'charged': 1801, 'reason': 'distance'}{'charged': 1801, 'reason': 'distance'}Passed
normal control 3{'charged': 1551, 'reason': 'destination'}{'charged': 1551, 'reason': 'destination'}Passed
normal control 4{'charged': 992, 'reason': 'destination'}{'charged': 992, 'reason': 'destination'}Passed

SHA-256 / 1a674edffa27764bd17c8b010acc691575905db2b054db4c3cf1628f53156043

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: time deviation ratio',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 5000, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 802, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1501, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 8001, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 1351, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1145, 'reason': 'time'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 5001, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1801, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D2', 'm': 8001, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1551, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 5000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 992, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 1002, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1710, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 4000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1041, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2813, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 10000, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2850, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1253, 's': 1351, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 807, 'reason': 'stops'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 10000, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2088, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 7801, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 7801, 's': 902, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1584, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 3999},
    {'dest': 'D2', 'm': 4000, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1841, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D2', 'm': 5000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1125, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D2', 'm': 3800, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1026, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 12001, 's': 601, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1720, 'reason': 'stops'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 12500, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 3999, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'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': 4000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 4000, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1240, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 1503, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1165, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D2', 'm': 10000, 's': 900, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1975, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 10002, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2876, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 1503, 's': 1202, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1089, 'reason': 'destination'})],
 [('regression: time deviation ratio',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 4000, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('partial repair probe: time deviation ratio',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 9800, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2678, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 1002, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 739, 'reason': 'time'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 12001, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2721, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 1252, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1389, 'reason': 'time'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 1253, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 938, 'reason': 'distance'})]]
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: time deviation ratio{'charged': 1250, 'reason': 'quote'}{'charged': 1250, 'reason': 'quote'}Passed
partial repair probe: time deviation ratio{'charged': 1501, 'reason': 'time'}{'charged': 1501, 'reason': 'time'}Passed
second regression{'charged': 2100, 'reason': 'quote'}{'charged': 2100, 'reason': 'quote'}Passed
normal control 1{'charged': 1145, 'reason': 'time'}{'charged': 1145, 'reason': 'time'}Passed
normal control 2{'charged': 1801, 'reason': 'distance'}{'charged': 1801, 'reason': 'distance'}Passed
normal control 3{'charged': 1551, 'reason': 'destination'}{'charged': 1551, 'reason': 'destination'}Passed
normal control 4{'charged': 992, 'reason': 'destination'}{'charged': 992, 'reason': 'destination'}Passed

SHA-256 / dda3f51fd52bf289860885727fb087da8551563a6e451631dbd7270a5564479a

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 2026-09-29T14:50:40.232155+00:00.

Case digest / 0517b94ecce14f5ce17ba8a21375816016beb2c2bc350dfcf3ace13d4bd216e2