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FA-85406 / Ride-hailing fare and surge pricing / Open access

Route exactly 25% longer voids the quote · case 01

A trip precisely at the 25% tolerance is repriced on the meter.

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

ROOT CAUSE

The deviation test uses >= against the tolerance.

VERIFIED REPAIR

Void the quote only when the route is strictly more than 25% longer.

Unsuccessful approach: Floor-dividing the tolerance and comparing with >= voids quotes below the threshold.

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'] * 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: distance deviation edge',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 5000, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 10001, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D2', 'm': 10002, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1750, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 10000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1826, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 15000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2476, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 802, 's': 1351, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1088, 'reason': 'destination'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 938, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 957, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 5000, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1092, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 3800, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 1002, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 12501, 's': 1800, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2813, 'reason': 'stops'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 12500, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10001, 's': 902, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1976, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 12001, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1820, 'reason': 'stops'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 3800, 's': 1200, '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': 3800, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1726, 'reason': 'time'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 802, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 12500, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2776, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 12500, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2164, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 1503, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1188, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 9800, 's': 2702, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2854, 'reason': 'time'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1242, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 1253, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1914, 'reason': 'distance'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2625, 'reason': 'time'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1976, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2225, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2330, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 10002, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1900, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D2', 'm': 10002, 's': 2702, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3026, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 10002, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2017, '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: distance deviation edge{'charged': 1650, 'reason': 'distance'}{'charged': 1250, 'reason': 'quote'}Failed
partial repair probe: distance deviation edge{'charged': 1250, 'reason': 'quote'}{'charged': 1250, 'reason': 'quote'}Passed
second regression{'charged': 1250, 'reason': 'quote'}{'charged': 1250, 'reason': 'quote'}Passed
normal control 1{'charged': 1750, 'reason': 'destination'}{'charged': 1750, 'reason': 'destination'}Passed
normal control 2{'charged': 1826, 'reason': 'destination'}{'charged': 1826, 'reason': 'destination'}Passed
normal control 3{'charged': 2476, 'reason': 'distance'}{'charged': 2476, 'reason': 'distance'}Passed
normal control 4{'charged': 1088, 'reason': 'destination'}{'charged': 1088, 'reason': 'destination'}Passed

SHA-256 / 6552a2b6606b0f17701217267843d21f24f7e9b4c59cdab845ca7fbc23df930d

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'] >= quote['est_m'] * 5 // 4:
        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: distance deviation edge',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 5000, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 10001, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D2', 'm': 10002, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1750, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 10000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1826, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 15000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2476, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 802, 's': 1351, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1088, 'reason': 'destination'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 938, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 957, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 5000, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1092, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 3800, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 1002, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 12501, 's': 1800, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2813, 'reason': 'stops'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 12500, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10001, 's': 902, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1976, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 12001, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1820, 'reason': 'stops'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 3800, 's': 1200, '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': 3800, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1726, 'reason': 'time'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 802, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 12500, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2776, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 12500, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2164, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 1503, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1188, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 9800, 's': 2702, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2854, 'reason': 'time'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1242, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 1253, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1914, 'reason': 'distance'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2625, 'reason': 'time'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1976, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2225, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2330, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 10002, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1900, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D2', 'm': 10002, 's': 2702, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3026, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 10002, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2017, '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: distance deviation edge{'charged': 1650, 'reason': 'distance'}{'charged': 1250, 'reason': 'quote'}Failed
partial repair probe: distance deviation edge{'charged': 2500, 'reason': 'distance'}{'charged': 1250, 'reason': 'quote'}Failed
second regression{'charged': 505, 'reason': 'distance'}{'charged': 1250, 'reason': 'quote'}Failed
normal control 1{'charged': 1750, 'reason': 'destination'}{'charged': 1750, 'reason': 'destination'}Passed
normal control 2{'charged': 1826, 'reason': 'destination'}{'charged': 1826, 'reason': 'destination'}Passed
normal control 3{'charged': 2476, 'reason': 'distance'}{'charged': 2476, 'reason': 'distance'}Passed
normal control 4{'charged': 1088, 'reason': 'destination'}{'charged': 1088, 'reason': 'destination'}Passed

SHA-256 / 8925ee35f59382fe64efce040e7754816c96edabc9d27f0de6c0d9740f716ec3

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: distance deviation edge',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 5000, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 10001, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 1252, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1250, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D2', 'm': 10002, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1750, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D2', 'm': 10000, 's': 901, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1826, 'reason': 'destination'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 1250},
    {'dest': 'D1', 'm': 15000, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2476, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 802, 's': 1351, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1088, 'reason': 'destination'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 601, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 938, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 1252, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 957, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 900, 'price': 3999},
    {'dest': 'D2', 'm': 5000, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1092, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 3800, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 1002, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 3999},
    {'dest': 'D1', 'm': 12501, 's': 1800, 'stops_added': 1}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2813, 'reason': 'stops'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1200, 'price': 1250},
    {'dest': 'D1', 'm': 12500, 's': 1200, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 10001, 's': 902, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1976, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2100, 'reason': 'quote'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 12001, 's': 900, 'stops_added': 1}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1820, 'reason': 'stops'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 3999},
    {'dest': 'D1', 'm': 3800, 's': 1200, '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': 3800, 's': 1801, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1726, 'reason': 'time'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 802, 's': 800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 1250},
    {'dest': 'D1', 'm': 12500, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1250, 'reason': 'quote'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 3602, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 2776, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 12500, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2164, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1200, 'price': 3999},
    {'dest': 'D2', 'm': 1503, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1188, 'reason': 'destination'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 9800, 's': 2702, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2854, 'reason': 'time'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 601, 'price': 3999},
    {'dest': 'D1', 'm': 6000, 's': 501, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 1242, 'reason': 'distance'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 1002, 'est_s': 1801, 'price': 3999},
    {'dest': 'D1', 'm': 1253, 's': 2701, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 1914, 'reason': 'distance'})],
 [('regression: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 900, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1800, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 35}],
   {'charged': 2625, 'reason': 'time'}),
  ('partial repair probe: distance deviation edge',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 601, 'price': 2100},
    {'dest': 'D1', 'm': 12500, 's': 1202, 'stops_added': 0}, {'base': 200, 'per_km': 110, 'per_min': 20}],
   {'charged': 1976, 'reason': 'time'}),
  ('second regression',
   [{'dest': 'D1', 'est_m': 4000, 'est_s': 1200, 'price': 2100},
    {'dest': 'D1', 'm': 5000, 's': 2400, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 2225, 'reason': 'time'}),
  ('normal control 1',
   [{'dest': 'D1', 'est_m': 10000, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 12501, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2330, 'reason': 'distance'}),
  ('normal control 2',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 900, 'price': 1250},
    {'dest': 'D1', 'm': 10002, 's': 1350, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 1900, 'reason': 'distance'}),
  ('normal control 3',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D2', 'm': 10002, 's': 2702, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 35}],
   {'charged': 3026, 'reason': 'destination'}),
  ('normal control 4',
   [{'dest': 'D1', 'est_m': 8001, 'est_s': 1801, 'price': 2100},
    {'dest': 'D1', 'm': 10002, 's': 1701, 'stops_added': 0}, {'base': 200, 'per_km': 125, 'per_min': 20}],
   {'charged': 2017, '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: distance deviation edge{'charged': 1250, 'reason': 'quote'}{'charged': 1250, 'reason': 'quote'}Passed
partial repair probe: distance deviation edge{'charged': 1250, 'reason': 'quote'}{'charged': 1250, 'reason': 'quote'}Passed
second regression{'charged': 1250, 'reason': 'quote'}{'charged': 1250, 'reason': 'quote'}Passed
normal control 1{'charged': 1750, 'reason': 'destination'}{'charged': 1750, 'reason': 'destination'}Passed
normal control 2{'charged': 1826, 'reason': 'destination'}{'charged': 1826, 'reason': 'destination'}Passed
normal control 3{'charged': 2476, 'reason': 'distance'}{'charged': 2476, 'reason': 'distance'}Passed
normal control 4{'charged': 1088, 'reason': 'destination'}{'charged': 1088, 'reason': 'destination'}Passed

SHA-256 / 538ed9f2efe53f1eed8f21d8dfe81d547c2dda181bc934afe69076c56b81b259

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 2026-09-29T14:50:40.019538+00:00.

Case digest / 2bb11a2c9bac076737b18404090ee9df8d12516a314356cfa26af2a0e9d911d1