FA-85661 / Ride-hailing fare and surge pricing / Open access

Requests stamped after now counted · case 01

Scheduled or skewed requests stamped in the future raise current demand.

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

ROOT CAUSE

The window lacks its upper bound.

VERIFIED REPAIR

Exclude requests with t > now.

Unsuccessful approach: An upper bound of now + window still admits future requests.

Case contract

Surge demand counts ride requests [t, rider, zone] in the window (now - window, now]. Each rider counts once, in the zone of their latest request in the window (a later-listed request wins a timestamp tie). Return zone -> count for zones with demand.

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(requests, now, window):
    latest = {}
    for t, rider, zone in requests:
        if now - window < t:
            key = rider
            if key not in latest or t >= latest[key][0]:
                latest[key] = (t, zone)
    out = {}
    for t, zone in latest.values():
        out[zone] = out.get(zone, 0) + 1
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: future-dated requests',
   [[[999, 'u2', 'Z2'], [700, 'u2', 'Z2'], [1001, 'u2', 'Z2'], [500, 'u2', 'Z2'], [1001, 'u3', 'Z2'],
     [401, 'u1', 'Z2'], [400, 'u2', 'Z2']],
    1000, 600],
   {'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[400, 'u3', 'Z1'], [1001, 'u3', 'Z2'], [700, 'u4', 'Z1'], [700, 'u1', 'Z2'], [1001, 'u3', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression',
   [[[401, 'u1', 'Z2'], [1001, 'u2', 'Z2'], [500, 'u1', 'Z2'], [999, 'u1', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 1',
   [[[700, 'u4', 'Z1'], [400, 'u2', 'Z2'], [401, 'u4', 'Z1'], [1000, 'u4', 'Z2']], 1000, 600], {'Z2': 1}),
  ('normal control 2',
   [[[400, 'u4', 'Z2'], [1000, 'u4', 'Z2'], [500, 'u4', 'Z1'], [999, 'u3', 'Z1'], [999, 'u2', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 3', [[[1000, 'u3', 'Z1'], [1000, 'u4', 'Z1']], 1000, 600], {'Z1': 2}),
  ('normal control 4',
   [[[500, 'u1', 'Z1'], [500, 'u1', 'Z1'], [700, 'u4', 'Z2'], [401, 'u3', 'Z2'], [400, 'u2', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 2})],
 [('regression: future-dated requests',
   [[[999, 'u3', 'Z2'], [1001, 'u1', 'Z2'], [400, 'u2', 'Z2'], [700, 'u2', 'Z1']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('partial repair probe: future-dated requests',
   [[[1000, 'u2', 'Z1'], [1000, 'u4', 'Z2'], [700, 'u2', 'Z1'], [1001, 'u2', 'Z2'], [401, 'u4', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression',
   [[[999, 'u1', 'Z1'], [400, 'u3', 'Z2'], [1001, 'u1', 'Z2'], [500, 'u3', 'Z2'], [401, 'u4', 'Z1'],
     [500, 'u1', 'Z2'], [999, 'u4', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 1',
   [[[1000, 'u3', 'Z2'], [500, 'u4', 'Z1'], [500, 'u1', 'Z1'], [1000, 'u4', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 2',
   [[[999, 'u3', 'Z1'], [1000, 'u1', 'Z2'], [999, 'u2', 'Z1'], [1001, 'u2', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 3',
   [[[500, 'u2', 'Z1'], [400, 'u4', 'Z1'], [1000, 'u4', 'Z2'], [1000, 'u3', 'Z2'], [1000, 'u3', 'Z2'],
     [700, 'u3', 'Z1'], [1000, 'u3', 'Z2'], [999, 'u2', 'Z1']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 4',
   [[[700, 'u3', 'Z2'], [999, 'u2', 'Z1'], [700, 'u1', 'Z1'], [500, 'u1', 'Z2']], 1000, 600],
   {'Z1': 2, 'Z2': 1})],
 [('regression: future-dated requests',
   [[[1000, 'u3', 'Z2'], [1001, 'u1', 'Z1'], [500, 'u2', 'Z2'], [1001, 'u1', 'Z1'], [999, 'u4', 'Z2'],
     [400, 'u3', 'Z2'], [1001, 'u1', 'Z1'], [1000, 'u2', 'Z2']],
    1000, 600],
   {'Z2': 3}),
  ('partial repair probe: future-dated requests',
   [[[400, 'u2', 'Z1'], [1001, 'u2', 'Z2'], [500, 'u2', 'Z2'], [500, 'u3', 'Z1'], [500, 'u3', 'Z1'],
     [500, 'u4', 'Z1'], [401, 'u3', 'Z1'], [1001, 'u1', 'Z1']],
    1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('second regression',
   [[[401, 'u1', 'Z1'], [999, 'u2', 'Z1'], [999, 'u4', 'Z1'], [1001, 'u4', 'Z2'], [500, 'u1', 'Z1']], 1000,
    600],
   {'Z1': 3}),
  ('normal control 1',
   [[[400, 'u4', 'Z2'], [999, 'u1', 'Z1'], [999, 'u4', 'Z2'], [700, 'u2', 'Z2'], [999, 'u1', 'Z2']], 1000,
    600],
   {'Z2': 3}),
  ('normal control 2',
   [[[401, 'u2', 'Z1'], [999, 'u4', 'Z1'], [700, 'u3', 'Z2'], [700, 'u3', 'Z2'], [400, 'u1', 'Z1'],
     [400, 'u4', 'Z1']],
    1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 3', [[[700, 'u1', 'Z1'], [500, 'u1', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 4',
   [[[999, 'u4', 'Z1'], [999, 'u3', 'Z2'], [700, 'u2', 'Z2'], [999, 'u2', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1})],
 [('regression: future-dated requests',
   [[[700, 'u2', 'Z2'], [999, 'u3', 'Z2'], [999, 'u4', 'Z2'], [1001, 'u1', 'Z2'], [1000, 'u2', 'Z2'],
     [999, 'u3', 'Z2'], [999, 'u4', 'Z1'], [401, 'u3', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[999, 'u1', 'Z1'], [1001, 'u2', 'Z2'], [1001, 'u1', 'Z1'], [700, 'u3', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression', [[[1001, 'u2', 'Z2'], [500, 'u3', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 1', [[[1000, 'u4', 'Z2'], [500, 'u3', 'Z2']], 1000, 600], {'Z2': 2}),
  ('normal control 2',
   [[[500, 'u2', 'Z1'], [700, 'u3', 'Z1'], [999, 'u4', 'Z2'], [999, 'u4', 'Z2'], [401, 'u3', 'Z2'],
     [400, 'u2', 'Z1'], [1000, 'u2', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 3', [[[1001, 'u2', 'Z1'], [400, 'u1', 'Z2'], [700, 'u2', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 4',
   [[[999, 'u4', 'Z2'], [401, 'u4', 'Z2'], [400, 'u2', 'Z2'], [400, 'u3', 'Z1'], [500, 'u1', 'Z2'],
     [401, 'u2', 'Z1'], [500, 'u2', 'Z1']],
    1000, 600],
   {'Z1': 1, 'Z2': 2})],
 [('regression: future-dated requests',
   [[[400, 'u1', 'Z1'], [1000, 'u1', 'Z2'], [500, 'u1', 'Z2'], [1001, 'u4', 'Z1'], [400, 'u3', 'Z2'],
     [700, 'u4', 'Z2']],
    1000, 600],
   {'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[1001, 'u2', 'Z2'], [1000, 'u3', 'Z2'], [500, 'u3', 'Z1']], 1000, 600], {'Z2': 1}),
  ('second regression',
   [[[1001, 'u3', 'Z1'], [999, 'u2', 'Z1'], [1001, 'u1', 'Z2'], [1000, 'u4', 'Z1'], [999, 'u1', 'Z1'],
     [1001, 'u4', 'Z2'], [1000, 'u3', 'Z1']],
    1000, 600],
   {'Z1': 4}),
  ('normal control 1', [[[1001, 'u2', 'Z2'], [700, 'u2', 'Z2']], 1000, 600], {'Z2': 1}),
  ('normal control 2',
   [[[400, 'u3', 'Z2'], [999, 'u2', 'Z1'], [999, 'u1', 'Z1'], [1000, 'u2', 'Z2'], [400, 'u1', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('normal control 3',
   [[[500, 'u2', 'Z2'], [999, 'u4', 'Z1'], [500, 'u4', 'Z2'], [400, 'u1', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('normal control 4',
   [[[999, 'u3', 'Z2'], [700, 'u4', 'Z1'], [400, 'u4', 'Z2'], [999, 'u2', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 2})]]
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 fixture	Actual	Expected	Outcome
regression: future-dated requests	`{'Z2': 3}`	`{'Z2': 2}`	Failed
partial repair probe: future-dated requests	`{'Z1': 1, 'Z2': 2}`	`{'Z1': 1, 'Z2': 1}`	Failed
second regression	`{'Z1': 1, 'Z2': 1}`	`{'Z1': 1}`	Failed
normal control 1	`{'Z2': 1}`	`{'Z2': 1}`	Passed
normal control 2	`{'Z1': 1, 'Z2': 2}`	`{'Z1': 1, 'Z2': 2}`	Passed
normal control 3	`{'Z1': 2}`	`{'Z1': 2}`	Passed
normal control 4	`{'Z1': 1, 'Z2': 2}`	`{'Z1': 1, 'Z2': 2}`	Passed

SHA-256 / a7dc1e3ec03d65d4962915a04ed4c51c9df230442265618422b5a1d14997a961

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(requests, now, window):
    latest = {}
    for t, rider, zone in requests:
        if now - window < t <= now + window:
            key = rider
            if key not in latest or t >= latest[key][0]:
                latest[key] = (t, zone)
    out = {}
    for t, zone in latest.values():
        out[zone] = out.get(zone, 0) + 1
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: future-dated requests',
   [[[999, 'u2', 'Z2'], [700, 'u2', 'Z2'], [1001, 'u2', 'Z2'], [500, 'u2', 'Z2'], [1001, 'u3', 'Z2'],
     [401, 'u1', 'Z2'], [400, 'u2', 'Z2']],
    1000, 600],
   {'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[400, 'u3', 'Z1'], [1001, 'u3', 'Z2'], [700, 'u4', 'Z1'], [700, 'u1', 'Z2'], [1001, 'u3', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression',
   [[[401, 'u1', 'Z2'], [1001, 'u2', 'Z2'], [500, 'u1', 'Z2'], [999, 'u1', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 1',
   [[[700, 'u4', 'Z1'], [400, 'u2', 'Z2'], [401, 'u4', 'Z1'], [1000, 'u4', 'Z2']], 1000, 600], {'Z2': 1}),
  ('normal control 2',
   [[[400, 'u4', 'Z2'], [1000, 'u4', 'Z2'], [500, 'u4', 'Z1'], [999, 'u3', 'Z1'], [999, 'u2', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 3', [[[1000, 'u3', 'Z1'], [1000, 'u4', 'Z1']], 1000, 600], {'Z1': 2}),
  ('normal control 4',
   [[[500, 'u1', 'Z1'], [500, 'u1', 'Z1'], [700, 'u4', 'Z2'], [401, 'u3', 'Z2'], [400, 'u2', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 2})],
 [('regression: future-dated requests',
   [[[999, 'u3', 'Z2'], [1001, 'u1', 'Z2'], [400, 'u2', 'Z2'], [700, 'u2', 'Z1']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('partial repair probe: future-dated requests',
   [[[1000, 'u2', 'Z1'], [1000, 'u4', 'Z2'], [700, 'u2', 'Z1'], [1001, 'u2', 'Z2'], [401, 'u4', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression',
   [[[999, 'u1', 'Z1'], [400, 'u3', 'Z2'], [1001, 'u1', 'Z2'], [500, 'u3', 'Z2'], [401, 'u4', 'Z1'],
     [500, 'u1', 'Z2'], [999, 'u4', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 1',
   [[[1000, 'u3', 'Z2'], [500, 'u4', 'Z1'], [500, 'u1', 'Z1'], [1000, 'u4', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 2',
   [[[999, 'u3', 'Z1'], [1000, 'u1', 'Z2'], [999, 'u2', 'Z1'], [1001, 'u2', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 3',
   [[[500, 'u2', 'Z1'], [400, 'u4', 'Z1'], [1000, 'u4', 'Z2'], [1000, 'u3', 'Z2'], [1000, 'u3', 'Z2'],
     [700, 'u3', 'Z1'], [1000, 'u3', 'Z2'], [999, 'u2', 'Z1']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 4',
   [[[700, 'u3', 'Z2'], [999, 'u2', 'Z1'], [700, 'u1', 'Z1'], [500, 'u1', 'Z2']], 1000, 600],
   {'Z1': 2, 'Z2': 1})],
 [('regression: future-dated requests',
   [[[1000, 'u3', 'Z2'], [1001, 'u1', 'Z1'], [500, 'u2', 'Z2'], [1001, 'u1', 'Z1'], [999, 'u4', 'Z2'],
     [400, 'u3', 'Z2'], [1001, 'u1', 'Z1'], [1000, 'u2', 'Z2']],
    1000, 600],
   {'Z2': 3}),
  ('partial repair probe: future-dated requests',
   [[[400, 'u2', 'Z1'], [1001, 'u2', 'Z2'], [500, 'u2', 'Z2'], [500, 'u3', 'Z1'], [500, 'u3', 'Z1'],
     [500, 'u4', 'Z1'], [401, 'u3', 'Z1'], [1001, 'u1', 'Z1']],
    1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('second regression',
   [[[401, 'u1', 'Z1'], [999, 'u2', 'Z1'], [999, 'u4', 'Z1'], [1001, 'u4', 'Z2'], [500, 'u1', 'Z1']], 1000,
    600],
   {'Z1': 3}),
  ('normal control 1',
   [[[400, 'u4', 'Z2'], [999, 'u1', 'Z1'], [999, 'u4', 'Z2'], [700, 'u2', 'Z2'], [999, 'u1', 'Z2']], 1000,
    600],
   {'Z2': 3}),
  ('normal control 2',
   [[[401, 'u2', 'Z1'], [999, 'u4', 'Z1'], [700, 'u3', 'Z2'], [700, 'u3', 'Z2'], [400, 'u1', 'Z1'],
     [400, 'u4', 'Z1']],
    1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 3', [[[700, 'u1', 'Z1'], [500, 'u1', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 4',
   [[[999, 'u4', 'Z1'], [999, 'u3', 'Z2'], [700, 'u2', 'Z2'], [999, 'u2', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1})],
 [('regression: future-dated requests',
   [[[700, 'u2', 'Z2'], [999, 'u3', 'Z2'], [999, 'u4', 'Z2'], [1001, 'u1', 'Z2'], [1000, 'u2', 'Z2'],
     [999, 'u3', 'Z2'], [999, 'u4', 'Z1'], [401, 'u3', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[999, 'u1', 'Z1'], [1001, 'u2', 'Z2'], [1001, 'u1', 'Z1'], [700, 'u3', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression', [[[1001, 'u2', 'Z2'], [500, 'u3', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 1', [[[1000, 'u4', 'Z2'], [500, 'u3', 'Z2']], 1000, 600], {'Z2': 2}),
  ('normal control 2',
   [[[500, 'u2', 'Z1'], [700, 'u3', 'Z1'], [999, 'u4', 'Z2'], [999, 'u4', 'Z2'], [401, 'u3', 'Z2'],
     [400, 'u2', 'Z1'], [1000, 'u2', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 3', [[[1001, 'u2', 'Z1'], [400, 'u1', 'Z2'], [700, 'u2', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 4',
   [[[999, 'u4', 'Z2'], [401, 'u4', 'Z2'], [400, 'u2', 'Z2'], [400, 'u3', 'Z1'], [500, 'u1', 'Z2'],
     [401, 'u2', 'Z1'], [500, 'u2', 'Z1']],
    1000, 600],
   {'Z1': 1, 'Z2': 2})],
 [('regression: future-dated requests',
   [[[400, 'u1', 'Z1'], [1000, 'u1', 'Z2'], [500, 'u1', 'Z2'], [1001, 'u4', 'Z1'], [400, 'u3', 'Z2'],
     [700, 'u4', 'Z2']],
    1000, 600],
   {'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[1001, 'u2', 'Z2'], [1000, 'u3', 'Z2'], [500, 'u3', 'Z1']], 1000, 600], {'Z2': 1}),
  ('second regression',
   [[[1001, 'u3', 'Z1'], [999, 'u2', 'Z1'], [1001, 'u1', 'Z2'], [1000, 'u4', 'Z1'], [999, 'u1', 'Z1'],
     [1001, 'u4', 'Z2'], [1000, 'u3', 'Z1']],
    1000, 600],
   {'Z1': 4}),
  ('normal control 1', [[[1001, 'u2', 'Z2'], [700, 'u2', 'Z2']], 1000, 600], {'Z2': 1}),
  ('normal control 2',
   [[[400, 'u3', 'Z2'], [999, 'u2', 'Z1'], [999, 'u1', 'Z1'], [1000, 'u2', 'Z2'], [400, 'u1', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('normal control 3',
   [[[500, 'u2', 'Z2'], [999, 'u4', 'Z1'], [500, 'u4', 'Z2'], [400, 'u1', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('normal control 4',
   [[[999, 'u3', 'Z2'], [700, 'u4', 'Z1'], [400, 'u4', 'Z2'], [999, 'u2', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 2})]]
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 fixture	Actual	Expected	Outcome
regression: future-dated requests	`{'Z2': 3}`	`{'Z2': 2}`	Failed
partial repair probe: future-dated requests	`{'Z1': 1, 'Z2': 2}`	`{'Z1': 1, 'Z2': 1}`	Failed
second regression	`{'Z1': 1, 'Z2': 1}`	`{'Z1': 1}`	Failed
normal control 1	`{'Z2': 1}`	`{'Z2': 1}`	Passed
normal control 2	`{'Z1': 1, 'Z2': 2}`	`{'Z1': 1, 'Z2': 2}`	Passed
normal control 3	`{'Z1': 2}`	`{'Z1': 2}`	Passed
normal control 4	`{'Z1': 1, 'Z2': 2}`	`{'Z1': 1, 'Z2': 2}`	Passed

SHA-256 / f5e20d20fef2a8e1bf927e8151c1c9a6a9cbea04dad251fd82bac5cd2ac71b23

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(requests, now, window):
    latest = {}
    for t, rider, zone in requests:
        if now - window < t <= now:
            key = rider
            if key not in latest or t >= latest[key][0]:
                latest[key] = (t, zone)
    out = {}
    for t, zone in latest.values():
        out[zone] = out.get(zone, 0) + 1
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: future-dated requests',
   [[[999, 'u2', 'Z2'], [700, 'u2', 'Z2'], [1001, 'u2', 'Z2'], [500, 'u2', 'Z2'], [1001, 'u3', 'Z2'],
     [401, 'u1', 'Z2'], [400, 'u2', 'Z2']],
    1000, 600],
   {'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[400, 'u3', 'Z1'], [1001, 'u3', 'Z2'], [700, 'u4', 'Z1'], [700, 'u1', 'Z2'], [1001, 'u3', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression',
   [[[401, 'u1', 'Z2'], [1001, 'u2', 'Z2'], [500, 'u1', 'Z2'], [999, 'u1', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 1',
   [[[700, 'u4', 'Z1'], [400, 'u2', 'Z2'], [401, 'u4', 'Z1'], [1000, 'u4', 'Z2']], 1000, 600], {'Z2': 1}),
  ('normal control 2',
   [[[400, 'u4', 'Z2'], [1000, 'u4', 'Z2'], [500, 'u4', 'Z1'], [999, 'u3', 'Z1'], [999, 'u2', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 3', [[[1000, 'u3', 'Z1'], [1000, 'u4', 'Z1']], 1000, 600], {'Z1': 2}),
  ('normal control 4',
   [[[500, 'u1', 'Z1'], [500, 'u1', 'Z1'], [700, 'u4', 'Z2'], [401, 'u3', 'Z2'], [400, 'u2', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 2})],
 [('regression: future-dated requests',
   [[[999, 'u3', 'Z2'], [1001, 'u1', 'Z2'], [400, 'u2', 'Z2'], [700, 'u2', 'Z1']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('partial repair probe: future-dated requests',
   [[[1000, 'u2', 'Z1'], [1000, 'u4', 'Z2'], [700, 'u2', 'Z1'], [1001, 'u2', 'Z2'], [401, 'u4', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression',
   [[[999, 'u1', 'Z1'], [400, 'u3', 'Z2'], [1001, 'u1', 'Z2'], [500, 'u3', 'Z2'], [401, 'u4', 'Z1'],
     [500, 'u1', 'Z2'], [999, 'u4', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 1',
   [[[1000, 'u3', 'Z2'], [500, 'u4', 'Z1'], [500, 'u1', 'Z1'], [1000, 'u4', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 2',
   [[[999, 'u3', 'Z1'], [1000, 'u1', 'Z2'], [999, 'u2', 'Z1'], [1001, 'u2', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 3',
   [[[500, 'u2', 'Z1'], [400, 'u4', 'Z1'], [1000, 'u4', 'Z2'], [1000, 'u3', 'Z2'], [1000, 'u3', 'Z2'],
     [700, 'u3', 'Z1'], [1000, 'u3', 'Z2'], [999, 'u2', 'Z1']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 4',
   [[[700, 'u3', 'Z2'], [999, 'u2', 'Z1'], [700, 'u1', 'Z1'], [500, 'u1', 'Z2']], 1000, 600],
   {'Z1': 2, 'Z2': 1})],
 [('regression: future-dated requests',
   [[[1000, 'u3', 'Z2'], [1001, 'u1', 'Z1'], [500, 'u2', 'Z2'], [1001, 'u1', 'Z1'], [999, 'u4', 'Z2'],
     [400, 'u3', 'Z2'], [1001, 'u1', 'Z1'], [1000, 'u2', 'Z2']],
    1000, 600],
   {'Z2': 3}),
  ('partial repair probe: future-dated requests',
   [[[400, 'u2', 'Z1'], [1001, 'u2', 'Z2'], [500, 'u2', 'Z2'], [500, 'u3', 'Z1'], [500, 'u3', 'Z1'],
     [500, 'u4', 'Z1'], [401, 'u3', 'Z1'], [1001, 'u1', 'Z1']],
    1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('second regression',
   [[[401, 'u1', 'Z1'], [999, 'u2', 'Z1'], [999, 'u4', 'Z1'], [1001, 'u4', 'Z2'], [500, 'u1', 'Z1']], 1000,
    600],
   {'Z1': 3}),
  ('normal control 1',
   [[[400, 'u4', 'Z2'], [999, 'u1', 'Z1'], [999, 'u4', 'Z2'], [700, 'u2', 'Z2'], [999, 'u1', 'Z2']], 1000,
    600],
   {'Z2': 3}),
  ('normal control 2',
   [[[401, 'u2', 'Z1'], [999, 'u4', 'Z1'], [700, 'u3', 'Z2'], [700, 'u3', 'Z2'], [400, 'u1', 'Z1'],
     [400, 'u4', 'Z1']],
    1000, 600],
   {'Z1': 2, 'Z2': 1}),
  ('normal control 3', [[[700, 'u1', 'Z1'], [500, 'u1', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 4',
   [[[999, 'u4', 'Z1'], [999, 'u3', 'Z2'], [700, 'u2', 'Z2'], [999, 'u2', 'Z1']], 1000, 600],
   {'Z1': 2, 'Z2': 1})],
 [('regression: future-dated requests',
   [[[700, 'u2', 'Z2'], [999, 'u3', 'Z2'], [999, 'u4', 'Z2'], [1001, 'u1', 'Z2'], [1000, 'u2', 'Z2'],
     [999, 'u3', 'Z2'], [999, 'u4', 'Z1'], [401, 'u3', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[999, 'u1', 'Z1'], [1001, 'u2', 'Z2'], [1001, 'u1', 'Z1'], [700, 'u3', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('second regression', [[[1001, 'u2', 'Z2'], [500, 'u3', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 1', [[[1000, 'u4', 'Z2'], [500, 'u3', 'Z2']], 1000, 600], {'Z2': 2}),
  ('normal control 2',
   [[[500, 'u2', 'Z1'], [700, 'u3', 'Z1'], [999, 'u4', 'Z2'], [999, 'u4', 'Z2'], [401, 'u3', 'Z2'],
     [400, 'u2', 'Z1'], [1000, 'u2', 'Z2']],
    1000, 600],
   {'Z1': 1, 'Z2': 2}),
  ('normal control 3', [[[1001, 'u2', 'Z1'], [400, 'u1', 'Z2'], [700, 'u2', 'Z1']], 1000, 600], {'Z1': 1}),
  ('normal control 4',
   [[[999, 'u4', 'Z2'], [401, 'u4', 'Z2'], [400, 'u2', 'Z2'], [400, 'u3', 'Z1'], [500, 'u1', 'Z2'],
     [401, 'u2', 'Z1'], [500, 'u2', 'Z1']],
    1000, 600],
   {'Z1': 1, 'Z2': 2})],
 [('regression: future-dated requests',
   [[[400, 'u1', 'Z1'], [1000, 'u1', 'Z2'], [500, 'u1', 'Z2'], [1001, 'u4', 'Z1'], [400, 'u3', 'Z2'],
     [700, 'u4', 'Z2']],
    1000, 600],
   {'Z2': 2}),
  ('partial repair probe: future-dated requests',
   [[[1001, 'u2', 'Z2'], [1000, 'u3', 'Z2'], [500, 'u3', 'Z1']], 1000, 600], {'Z2': 1}),
  ('second regression',
   [[[1001, 'u3', 'Z1'], [999, 'u2', 'Z1'], [1001, 'u1', 'Z2'], [1000, 'u4', 'Z1'], [999, 'u1', 'Z1'],
     [1001, 'u4', 'Z2'], [1000, 'u3', 'Z1']],
    1000, 600],
   {'Z1': 4}),
  ('normal control 1', [[[1001, 'u2', 'Z2'], [700, 'u2', 'Z2']], 1000, 600], {'Z2': 1}),
  ('normal control 2',
   [[[400, 'u3', 'Z2'], [999, 'u2', 'Z1'], [999, 'u1', 'Z1'], [1000, 'u2', 'Z2'], [400, 'u1', 'Z2']], 1000,
    600],
   {'Z1': 1, 'Z2': 1}),
  ('normal control 3',
   [[[500, 'u2', 'Z2'], [999, 'u4', 'Z1'], [500, 'u4', 'Z2'], [400, 'u1', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 1}),
  ('normal control 4',
   [[[999, 'u3', 'Z2'], [700, 'u4', 'Z1'], [400, 'u4', 'Z2'], [999, 'u2', 'Z2']], 1000, 600],
   {'Z1': 1, 'Z2': 2})]]
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 fixture	Actual	Expected	Outcome
regression: future-dated requests	`{'Z2': 2}`	`{'Z2': 2}`	Passed
partial repair probe: future-dated requests	`{'Z1': 1, 'Z2': 1}`	`{'Z1': 1, 'Z2': 1}`	Passed
second regression	`{'Z1': 1}`	`{'Z1': 1}`	Passed
normal control 1	`{'Z2': 1}`	`{'Z2': 1}`	Passed
normal control 2	`{'Z1': 1, 'Z2': 2}`	`{'Z1': 1, 'Z2': 2}`	Passed
normal control 3	`{'Z1': 2}`	`{'Z1': 2}`	Passed
normal control 4	`{'Z1': 1, 'Z2': 2}`	`{'Z1': 1, 'Z2': 2}`	Passed

SHA-256 / 88577e9bf3444ba1dcc697073885cb51ad2bdd364cf2ec4019fac5d4c9e29f01

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 2026-09-29T14:50:42.445949+00:00.

Case digest / 65a31a4b94c2a300ff56f035092074dfcefd056702c15647bbb36aa8a498218e