FA-94716 / Exam timetabling constraints / Open access

Weekday names mapped with a Sunday-first table · case 01

A Friday-evening restriction is enforced on Saturday.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Weekday index 0 is named Sunday although periods use Monday = 0.

THE FAILURE

Weekday index 0 is named Sunday although periods use Monday = 0.

Unsuccessful approach: Shifting the index forward moves the restriction the other way.

Case contract

sits [student, exam, period]; periods index -> [weekday 0=Mon..6=Sun, slot am/pm/eve]; avoid student -> rules "day" (whole day) or "day-slot" (that slot and later slots that day). Each sitting matching any rule is reported once as [student, exam, period]; return rows sorted.

Why this case matters

Religious-observance and other unavailability constraints are student-specific hard constraints.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(sits, periods, avoid):
    names = ['sun', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat']
    order = ['am', 'pm', 'eve']
    out = []
    for st, ex, p in sits:
        wd, slot = periods[p]
        for rule in avoid.get(st, []):
            parts = rule.split('-')
            if parts[0] != names[wd]:
                continue
            if len(parts) == 1 or order.index(slot) >= order.index(parts[1]):
                out.append([st, ex, p])
                break
    return sorted(out)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: weekday names 1', [[['s1', 'A', 0]], [[4, 'eve']], {'s1': ['fri-pm']}], [['s1', 'A', 0]]),
  ('regression variant: weekday names 2',
   [[['s3', 'MATH101', 0], ['s1', 'CHEM120', 2], ['s3', 'MATH101', 1], ['s2', 'CHEM120', 1],
     ['s1', 'BIO130', 2]],
    [[3, 'am'], [4, 'eve'], [1, 'eve'], [1, 'pm'], [0, 'pm'], [4, 'am']],
    {'s1': ['sat'], 's3': ['fri', 'sun-am']}],
   [['s3', 'MATH101', 1]]),
  ('partial repair guard 3',
   [[['s3', 'MATH101', 0]], [[5, 'eve'], [0, 'pm'], [2, 'am'], [5, 'eve'], [1, 'eve'], [3, 'am']],
    {'s1': ['fri', 'fri-eve'], 's3': ['sun-am']}],
   []),
  ('boundary control 4', [[['s1', 'A', 0]], [[4, 'eve']], {'s1': ['fri-eve', 'fri-pm']}], [['s1', 'A', 0]]),
  ('normal control 5',
   [[['s1', 'CHEM120', 3], ['s1', 'BIO130', 4], ['s2', 'ECON150', 4], ['s1', 'HIST140', 0],
     ['s1', 'CHEM120', 1]],
    [[6, 'pm'], [3, 'pm'], [5, 'pm'], [0, 'eve'], [6, 'am'], [1, 'am']],
    {'s1': ['mon-eve', 'fri', 'sun-am'], 's2': ['sat', 'fri-pm', 'fri']}],
   [['s1', 'BIO130', 4], ['s1', 'CHEM120', 3], ['s1', 'HIST140', 0]]),
  ('normal control 6',
   [[['s1', 'PHYS110', 1], ['s3', 'CHEM120', 4], ['s3', 'MATH101H', 2], ['s3', 'MATH101', 3]],
    [[1, 'am'], [1, 'pm'], [6, 'pm'], [1, 'pm'], [2, 'eve'], [3, 'pm']],
    {'s1': ['fri', 'mon-eve'], 's2': ['mon-eve', 'sun-am'], 's3': ['sat']}],
   []),
  ('normal control 7',
   [[['s1', 'ECON150', 3]], [[2, 'eve'], [6, 'pm'], [0, 'eve'], [3, 'eve'], [4, 'pm'], [0, 'pm']],
    {'s3': ['fri', 'mon-eve', 'fri-eve']}],
   []),
  ('normal control 8',
   [[['s1', 'ECON150', 2], ['s1', 'ECON150', 1], ['s3', 'PHYS110', 2], ['s1', 'BIO130', 0]],
    [[4, 'pm'], [4, 'eve'], [2, 'am'], [0, 'am'], [6, 'pm'], [5, 'pm']],
    {'s1': ['mon-eve', 'sun-am', 'fri'], 's2': ['fri', 'sun-am', 'fri-eve'], 's3': ['sun-am', 'fri']}],
   [['s1', 'BIO130', 0], ['s1', 'ECON150', 1]])],
 [('regression: weekday names 1', [[['s1', 'A', 0]], [[5, 'am']], {'s1': ['sat', 'fri-pm']}],
   [['s1', 'A', 0]]),
  ('regression variant: weekday names 2',
   [[['s3', 'MATH101H', 2]], [[3, 'pm'], [4, 'pm'], [1, 'eve'], [5, 'am'], [3, 'am'], [2, 'pm']],
    {'s1': ['sun-am'], 's2': ['mon-eve', 'fri-eve'], 's3': ['mon-eve', 'fri']}],
   []),
  ('partial repair guard 3',
   [[['s2', 'MATH101', 2], ['s3', 'MATH101', 3], ['s3', 'BIO130', 3], ['s1', 'ECON150', 2],
     ['s3', 'BIO130', 1], ['s1', 'BIO130', 1]],
    [[2, 'am'], [5, 'pm'], [0, 'am'], [5, 'pm'], [6, 'pm'], [6, 'am']],
    {'s2': ['sat', 'fri-pm', 'fri'], 's3': ['fri-pm', 'fri-eve', 'sat']}],
   [['s3', 'BIO130', 1], ['s3', 'BIO130', 3], ['s3', 'MATH101', 3]]),
  ('boundary control 4', [[['s1', 'A', 0]], [[4, 'am']], {'s1': ['fri-pm']}], []),
  ('normal control 5',
   [[['s2', 'HIST140', 1], ['s1', 'MATH101', 1], ['s2', 'HIST140', 5]],
    [[4, 'pm'], [4, 'am'], [2, 'eve'], [5, 'eve'], [0, 'am'], [2, 'pm']],
    {'s1': ['fri', 'fri-pm'], 's2': ['fri-eve', 'fri', 'mon-eve'], 's3': ['fri-pm', 'sun-am']}],
   [['s1', 'MATH101', 1], ['s2', 'HIST140', 1]]),
  ('normal control 6',
   [[['s1', 'MATH101H', 1], ['s3', 'MATH101', 0], ['s3', 'MATH101', 0], ['s2', 'PHYS110', 4],
     ['s2', 'BIO130', 1]],
    [[6, 'eve'], [5, 'am'], [5, 'eve'], [0, 'pm'], [5, 'am'], [0, 'pm']],
    {'s1': ['sat', 'mon-eve'], 's2': ['fri'], 's3': ['fri-pm', 'sun-am']}],
   [['s1', 'MATH101H', 1], ['s3', 'MATH101', 0], ['s3', 'MATH101', 0]]),
  ('normal control 7',
   [[['s3', 'CHEM120', 4], ['s3', 'BIO130', 4]],
    [[1, 'eve'], [0, 'am'], [0, 'am'], [5, 'am'], [0, 'eve'], [2, 'am']],
    {'s1': ['mon-eve', 'fri', 'sun-am'], 's2': ['fri-eve', 'mon-eve', 'fri-pm'], 's3': ['sat']}],
   []),
  ('normal control 8',
   [[['s2', 'BIO130', 1], ['s1', 'ECON150', 2]],
    [[4, 'pm'], [5, 'eve'], [0, 'eve'], [5, 'am'], [1, 'am'], [0, 'pm']],
    {'s1': ['sat'], 's2': ['fri'], 's3': ['mon-eve']}],
   [])],
 [('regression: weekday names 1', [[['s1', 'A', 0]], [[4, 'eve']], {'s1': ['fri-eve', 'fri-pm']}],
   [['s1', 'A', 0]]),
  ('regression variant: weekday names 2',
   [[['s1', 'HIST140', 2], ['s3', 'MATH101H', 1], ['s1', 'CHEM120', 4], ['s2', 'CHEM120', 4],
     ['s2', 'MATH101', 4], ['s3', 'MATH101H', 5]],
    [[0, 'eve'], [4, 'eve'], [4, 'pm'], [4, 'pm'], [5, 'pm'], [0, 'pm']],
    {'s1': ['fri-eve', 'sat', 'mon-eve'],
     's2': ['mon-eve', 'fri', 'sun-am'],
     's3': ['sun-am', 'fri-pm', 'fri']}],
   [['s1', 'CHEM120', 4], ['s3', 'MATH101H', 1]]),
  ('partial repair guard 3',
   [[['s3', 'PHYS110', 2], ['s2', 'BIO130', 4]],
    [[3, 'pm'], [5, 'pm'], [0, 'pm'], [5, 'am'], [5, 'eve'], [4, 'am']],
    {'s2': ['fri', 'sat', 'fri-pm'], 's3': ['sat', 'fri-eve', 'mon-eve']}],
   [['s2', 'BIO130', 4]]),
  ('boundary control 4', [[['s1', 'A', 0]], [[0, 'am']], {'s1': ['sun']}], []),
  ('normal control 5',
   [[['s3', 'MATH101H', 4], ['s2', 'PHYS110', 1]],
    [[4, 'am'], [2, 'am'], [4, 'am'], [0, 'eve'], [0, 'eve'], [5, 'pm']],
    {'s1': ['fri-pm', 'sat', 'fri-eve'], 's2': ['fri', 'sun-am', 'sat'], 's3': ['fri-eve']}],
   []),
  ('normal control 6',
   [[['s1', 'CHEM120', 2], ['s2', 'CHEM120', 3], ['s3', 'PHYS110', 3], ['s3', 'BIO130', 5],
     ['s3', 'BIO130', 2], ['s3', 'MATH101H', 1]],
    [[4, 'eve'], [6, 'am'], [2, 'am'], [2, 'am'], [1, 'am'], [4, 'eve']],
    {'s1': ['sat', 'fri-pm', 'mon-eve'], 's2': ['mon-eve'], 's3': ['fri']}],
   [['s3', 'BIO130', 5]]),
  ('normal control 7',
   [[['s1', 'MATH101', 5], ['s3', 'ECON150', 4], ['s1', 'ECON150', 5], ['s3', 'MATH101H', 3],
     ['s1', 'MATH101H', 1], ['s3', 'PHYS110', 3]],
    [[1, 'eve'], [3, 'am'], [2, 'pm'], [3, 'am'], [3, 'eve'], [4, 'pm']],
    {'s1': ['sun-am', 'mon-eve'], 's2': ['mon-eve', 'sun-am', 'fri'], 's3': ['fri-eve', 'sun-am', 'fri']}],
   []),
  ('normal control 8',
   [[['s3', 'PHYS110', 2], ['s2', 'HIST140', 4], ['s2', 'MATH101', 0]],
    [[3, 'pm'], [1, 'am'], [6, 'am'], [0, 'pm'], [5, 'pm'], [5, 'am']],
    {'s1': ['fri-pm'], 's2': ['fri', 'mon-eve'], 's3': ['fri-pm', 'sun-am', 'mon-eve']}],
   [['s3', 'PHYS110', 2]])],
 [('regression: weekday names 1', [[['s1', 'A', 0]], [[0, 'am']], {'s1': ['sun']}], []),
  ('regression variant: weekday names 2',
   [[['s2', 'ECON150', 5]], [[1, 'pm'], [2, 'eve'], [4, 'pm'], [4, 'am'], [1, 'eve'], [1, 'eve']],
    {'s1': ['sat', 'fri-pm', 'fri'], 's2': ['mon-eve'], 's3': ['fri-pm', 'mon-eve', 'fri-eve']}],
   []),
  ('partial repair guard 3',
   [[['s3', 'PHYS110', 2], ['s2', 'MATH101', 1], ['s3', 'PHYS110', 5], ['s1', 'MATH101H', 1],
     ['s2', 'CHEM120', 5], ['s1', 'MATH101', 0]],
    [[4, 'eve'], [4, 'pm'], [0, 'pm'], [2, 'eve'], [0, 'am'], [4, 'pm']],
    {'s1': ['sun-am', 'mon-eve'], 's2': ['sat', 'mon-eve'], 's3': ['sun-am']}],
   []),
  ('boundary control 4', [[['s1', 'A', 0]], [[5, 'am']], {'s1': ['sat', 'fri-pm']}], [['s1', 'A', 0]]),
  ('normal control 5',
   [[['s1', 'ECON150', 5], ['s1', 'HIST140', 0], ['s3', 'CHEM120', 2], ['s1', 'HIST140', 4],
     ['s3', 'ECON150', 2]],
    [[2, 'eve'], [5, 'pm'], [6, 'pm'], [6, 'eve'], [1, 'am'], [0, 'am']],
    {'s1': ['sat'], 's2': ['fri', 'fri-eve', 'sat']}],
   []),
  ('normal control 6',
   [[['s2', 'MATH101H', 2], ['s1', 'ECON150', 1], ['s1', 'ECON150', 2]],
    [[3, 'eve'], [5, 'am'], [2, 'am'], [2, 'pm'], [4, 'am'], [2, 'pm']],
    {'s1': ['fri', 'sat'], 's2': ['fri-eve', 'sun-am', 'fri'], 's3': ['fri', 'sun-am', 'mon-eve']}],
   [['s1', 'ECON150', 1]]),
  ('normal control 7',
   [[['s1', 'CHEM120', 5], ['s3', 'CHEM120', 4], ['s2', 'CHEM120', 4], ['s1', 'PHYS110', 4]],
    [[5, 'eve'], [3, 'am'], [6, 'am'], [5, 'am'], [1, 'am'], [3, 'pm']],
    {'s1': ['fri'], 's2': ['mon-eve', 'fri-eve']}],
   []),
  ('normal control 8',
   [[['s2', 'MATH101H', 5], ['s1', 'BIO130', 1], ['s3', 'MATH101', 3], ['s3', 'ECON150', 1],
     ['s3', 'PHYS110', 1]],
    [[1, 'pm'], [5, 'am'], [6, 'eve'], [5, 'eve'], [3, 'am'], [5, 'pm']], {'s3': ['fri-pm']}],
   [])],
 [('regression: weekday names 1',
   [[['s2', 'PHYS110', 4], ['s3', 'BIO130', 3], ['s1', 'CHEM120', 1], ['s1', 'HIST140', 5],
     ['s3', 'HIST140', 3], ['s3', 'HIST140', 5]],
    [[5, 'eve'], [3, 'eve'], [1, 'eve'], [6, 'eve'], [0, 'am'], [5, 'am']],
    {'s1': ['mon-eve', 'sat'], 's2': ['fri-pm'], 's3': ['mon-eve', 'sun-am']}],
   [['s1', 'HIST140', 5], ['s3', 'BIO130', 3], ['s3', 'HIST140', 3]]),
  ('regression variant: weekday names 2',
   [[['s3', 'MATH101', 1], ['s2', 'PHYS110', 0], ['s2', 'MATH101H', 4], ['s1', 'HIST140', 4],
     ['s3', 'BIO130', 1], ['s1', 'ECON150', 5]],
    [[4, 'eve'], [5, 'pm'], [1, 'am'], [1, 'pm'], [5, 'am'], [0, 'pm']],
    {'s1': ['fri-eve'], 's2': ['sun-am', 'fri', 'mon-eve'], 's3': ['mon-eve', 'fri-eve', 'fri-pm']}],
   [['s2', 'PHYS110', 0]]),
  ('partial repair guard 3',
   [[['s1', 'PHYS110', 2], ['s3', 'HIST140', 0], ['s3', 'PHYS110', 1]],
    [[0, 'pm'], [5, 'pm'], [4, 'eve'], [6, 'am'], [6, 'am'], [0, 'pm']],
    {'s1': ['sun-am', 'fri'], 's2': ['fri-pm', 'sun-am', 'fri-eve']}],
   [['s1', 'PHYS110', 2]]),
  ('boundary control 4', [[['s1', 'A', 0]], [[4, 'eve']], {'s1': ['fri-pm']}], [['s1', 'A', 0]]),
  ('normal control 5',
   [[['s1', 'MATH101H', 3], ['s3', 'MATH101H', 4], ['s2', 'CHEM120', 1]],
    [[2, 'eve'], [4, 'pm'], [6, 'pm'], [2, 'eve'], [2, 'am'], [0, 'eve']], {'s3': ['fri-eve']}],
   []),
  ('normal control 6',
   [[['s2', 'PHYS110', 4], ['s1', 'ECON150', 0], ['s2', 'ECON150', 2], ['s3', 'PHYS110', 4],
     ['s2', 'HIST140', 0]],
    [[3, 'pm'], [0, 'pm'], [5, 'pm'], [1, 'pm'], [1, 'pm'], [4, 'am']],
    {'s1': ['fri', 'mon-eve', 'fri-pm'], 's2': ['sat'], 's3': ['sat', 'fri', 'sun-am']}],
   [['s2', 'ECON150', 2]]),
  ('normal control 7',
   [[['s2', 'MATH101H', 0], ['s1', 'CHEM120', 4], ['s1', 'HIST140', 2], ['s2', 'BIO130', 3]],
    [[4, 'am'], [3, 'pm'], [6, 'eve'], [3, 'pm'], [4, 'pm'], [4, 'pm']],
    {'s1': ['fri-pm'], 's2': ['fri'], 's3': ['fri-pm', 'mon-eve', 'sun-am']}],
   [['s1', 'CHEM120', 4], ['s2', 'MATH101H', 0]]),
  ('normal control 8',
   [[['s1', 'BIO130', 3]], [[5, 'am'], [5, 'am'], [0, 'am'], [1, 'pm'], [3, 'am'], [6, 'am']],
    {'s2': ['sun-am', 'sat', 'mon-eve'], 's3': ['sat', 'sun-am']}],
   [])]]
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: weekday names 1	`[]`	`[['s1', 'A', 0]]`	Failed
regression variant: weekday names 2	`[]`	`[['s3', 'MATH101', 1]]`	Failed
partial repair guard 3	`[]`	`[]`	Passed
boundary control 4	`[]`	`[['s1', 'A', 0]]`	Failed
normal control 5	`[['s1', 'CHEM120', 3], ['s2', 'ECON150', 4]]`	`[['s1', 'BIO130', 4], ['s1', 'CHEM120', 3], ['s1', 'HIST140', 0]]`	Failed
normal control 6	`[['s3', 'MATH101H', 2]]`	`[]`	Failed
normal control 7	`[]`	`[]`	Passed
normal control 8	`[]`	`[['s1', 'BIO130', 0], ['s1', 'ECON150', 1]]`	Failed

SHA-256 / d1e312502654c5cd17334a677dc09872d58c116b2d649f179874140bf8dda3fe

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(sits, periods, avoid):
    names = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
    order = ['am', 'pm', 'eve']
    out = []
    for st, ex, p in sits:
        wd, slot = periods[p]
        for rule in avoid.get(st, []):
            parts = rule.split('-')
            if parts[0] != names[(wd + 1) % 7]:
                continue
            if len(parts) == 1 or order.index(slot) >= order.index(parts[1]):
                out.append([st, ex, p])
                break
    return sorted(out)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: weekday names 1', [[['s1', 'A', 0]], [[4, 'eve']], {'s1': ['fri-pm']}], [['s1', 'A', 0]]),
  ('regression variant: weekday names 2',
   [[['s3', 'MATH101', 0], ['s1', 'CHEM120', 2], ['s3', 'MATH101', 1], ['s2', 'CHEM120', 1],
     ['s1', 'BIO130', 2]],
    [[3, 'am'], [4, 'eve'], [1, 'eve'], [1, 'pm'], [0, 'pm'], [4, 'am']],
    {'s1': ['sat'], 's3': ['fri', 'sun-am']}],
   [['s3', 'MATH101', 1]]),
  ('partial repair guard 3',
   [[['s3', 'MATH101', 0]], [[5, 'eve'], [0, 'pm'], [2, 'am'], [5, 'eve'], [1, 'eve'], [3, 'am']],
    {'s1': ['fri', 'fri-eve'], 's3': ['sun-am']}],
   []),
  ('boundary control 4', [[['s1', 'A', 0]], [[4, 'eve']], {'s1': ['fri-eve', 'fri-pm']}], [['s1', 'A', 0]]),
  ('normal control 5',
   [[['s1', 'CHEM120', 3], ['s1', 'BIO130', 4], ['s2', 'ECON150', 4], ['s1', 'HIST140', 0],
     ['s1', 'CHEM120', 1]],
    [[6, 'pm'], [3, 'pm'], [5, 'pm'], [0, 'eve'], [6, 'am'], [1, 'am']],
    {'s1': ['mon-eve', 'fri', 'sun-am'], 's2': ['sat', 'fri-pm', 'fri']}],
   [['s1', 'BIO130', 4], ['s1', 'CHEM120', 3], ['s1', 'HIST140', 0]]),
  ('normal control 6',
   [[['s1', 'PHYS110', 1], ['s3', 'CHEM120', 4], ['s3', 'MATH101H', 2], ['s3', 'MATH101', 3]],
    [[1, 'am'], [1, 'pm'], [6, 'pm'], [1, 'pm'], [2, 'eve'], [3, 'pm']],
    {'s1': ['fri', 'mon-eve'], 's2': ['mon-eve', 'sun-am'], 's3': ['sat']}],
   []),
  ('normal control 7',
   [[['s1', 'ECON150', 3]], [[2, 'eve'], [6, 'pm'], [0, 'eve'], [3, 'eve'], [4, 'pm'], [0, 'pm']],
    {'s3': ['fri', 'mon-eve', 'fri-eve']}],
   []),
  ('normal control 8',
   [[['s1', 'ECON150', 2], ['s1', 'ECON150', 1], ['s3', 'PHYS110', 2], ['s1', 'BIO130', 0]],
    [[4, 'pm'], [4, 'eve'], [2, 'am'], [0, 'am'], [6, 'pm'], [5, 'pm']],
    {'s1': ['mon-eve', 'sun-am', 'fri'], 's2': ['fri', 'sun-am', 'fri-eve'], 's3': ['sun-am', 'fri']}],
   [['s1', 'BIO130', 0], ['s1', 'ECON150', 1]])],
 [('regression: weekday names 1', [[['s1', 'A', 0]], [[5, 'am']], {'s1': ['sat', 'fri-pm']}],
   [['s1', 'A', 0]]),
  ('regression variant: weekday names 2',
   [[['s3', 'MATH101H', 2]], [[3, 'pm'], [4, 'pm'], [1, 'eve'], [5, 'am'], [3, 'am'], [2, 'pm']],
    {'s1': ['sun-am'], 's2': ['mon-eve', 'fri-eve'], 's3': ['mon-eve', 'fri']}],
   []),
  ('partial repair guard 3',
   [[['s2', 'MATH101', 2], ['s3', 'MATH101', 3], ['s3', 'BIO130', 3], ['s1', 'ECON150', 2],
     ['s3', 'BIO130', 1], ['s1', 'BIO130', 1]],
    [[2, 'am'], [5, 'pm'], [0, 'am'], [5, 'pm'], [6, 'pm'], [6, 'am']],
    {'s2': ['sat', 'fri-pm', 'fri'], 's3': ['fri-pm', 'fri-eve', 'sat']}],
   [['s3', 'BIO130', 1], ['s3', 'BIO130', 3], ['s3', 'MATH101', 3]]),
  ('boundary control 4', [[['s1', 'A', 0]], [[4, 'am']], {'s1': ['fri-pm']}], []),
  ('normal control 5',
   [[['s2', 'HIST140', 1], ['s1', 'MATH101', 1], ['s2', 'HIST140', 5]],
    [[4, 'pm'], [4, 'am'], [2, 'eve'], [5, 'eve'], [0, 'am'], [2, 'pm']],
    {'s1': ['fri', 'fri-pm'], 's2': ['fri-eve', 'fri', 'mon-eve'], 's3': ['fri-pm', 'sun-am']}],
   [['s1', 'MATH101', 1], ['s2', 'HIST140', 1]]),
  ('normal control 6',
   [[['s1', 'MATH101H', 1], ['s3', 'MATH101', 0], ['s3', 'MATH101', 0], ['s2', 'PHYS110', 4],
     ['s2', 'BIO130', 1]],
    [[6, 'eve'], [5, 'am'], [5, 'eve'], [0, 'pm'], [5, 'am'], [0, 'pm']],
    {'s1': ['sat', 'mon-eve'], 's2': ['fri'], 's3': ['fri-pm', 'sun-am']}],
   [['s1', 'MATH101H', 1], ['s3', 'MATH101', 0], ['s3', 'MATH101', 0]]),
  ('normal control 7',
   [[['s3', 'CHEM120', 4], ['s3', 'BIO130', 4]],
    [[1, 'eve'], [0, 'am'], [0, 'am'], [5, 'am'], [0, 'eve'], [2, 'am']],
    {'s1': ['mon-eve', 'fri', 'sun-am'], 's2': ['fri-eve', 'mon-eve', 'fri-pm'], 's3': ['sat']}],
   []),
  ('normal control 8',
   [[['s2', 'BIO130', 1], ['s1', 'ECON150', 2]],
    [[4, 'pm'], [5, 'eve'], [0, 'eve'], [5, 'am'], [1, 'am'], [0, 'pm']],
    {'s1': ['sat'], 's2': ['fri'], 's3': ['mon-eve']}],
   [])],
 [('regression: weekday names 1', [[['s1', 'A', 0]], [[4, 'eve']], {'s1': ['fri-eve', 'fri-pm']}],
   [['s1', 'A', 0]]),
  ('regression variant: weekday names 2',
   [[['s1', 'HIST140', 2], ['s3', 'MATH101H', 1], ['s1', 'CHEM120', 4], ['s2', 'CHEM120', 4],
     ['s2', 'MATH101', 4], ['s3', 'MATH101H', 5]],
    [[0, 'eve'], [4, 'eve'], [4, 'pm'], [4, 'pm'], [5, 'pm'], [0, 'pm']],
    {'s1': ['fri-eve', 'sat', 'mon-eve'],
     's2': ['mon-eve', 'fri', 'sun-am'],
     's3': ['sun-am', 'fri-pm', 'fri']}],
   [['s1', 'CHEM120', 4], ['s3', 'MATH101H', 1]]),
  ('partial repair guard 3',
   [[['s3', 'PHYS110', 2], ['s2', 'BIO130', 4]],
    [[3, 'pm'], [5, 'pm'], [0, 'pm'], [5, 'am'], [5, 'eve'], [4, 'am']],
    {'s2': ['fri', 'sat', 'fri-pm'], 's3': ['sat', 'fri-eve', 'mon-eve']}],
   [['s2', 'BIO130', 4]]),
  ('boundary control 4', [[['s1', 'A', 0]], [[0, 'am']], {'s1': ['sun']}], []),
  ('normal control 5',
   [[['s3', 'MATH101H', 4], ['s2', 'PHYS110', 1]],
    [[4, 'am'], [2, 'am'], [4, 'am'], [0, 'eve'], [0, 'eve'], [5, 'pm']],
    {'s1': ['fri-pm', 'sat', 'fri-eve'], 's2': ['fri', 'sun-am', 'sat'], 's3': ['fri-eve']}],
   []),
  ('normal control 6',
   [[['s1', 'CHEM120', 2], ['s2', 'CHEM120', 3], ['s3', 'PHYS110', 3], ['s3', 'BIO130', 5],
     ['s3', 'BIO130', 2], ['s3', 'MATH101H', 1]],
    [[4, 'eve'], [6, 'am'], [2, 'am'], [2, 'am'], [1, 'am'], [4, 'eve']],
    {'s1': ['sat', 'fri-pm', 'mon-eve'], 's2': ['mon-eve'], 's3': ['fri']}],
   [['s3', 'BIO130', 5]]),
  ('normal control 7',
   [[['s1', 'MATH101', 5], ['s3', 'ECON150', 4], ['s1', 'ECON150', 5], ['s3', 'MATH101H', 3],
     ['s1', 'MATH101H', 1], ['s3', 'PHYS110', 3]],
    [[1, 'eve'], [3, 'am'], [2, 'pm'], [3, 'am'], [3, 'eve'], [4, 'pm']],
    {'s1': ['sun-am', 'mon-eve'], 's2': ['mon-eve', 'sun-am', 'fri'], 's3': ['fri-eve', 'sun-am', 'fri']}],
   []),
  ('normal control 8',
   [[['s3', 'PHYS110', 2], ['s2', 'HIST140', 4], ['s2', 'MATH101', 0]],
    [[3, 'pm'], [1, 'am'], [6, 'am'], [0, 'pm'], [5, 'pm'], [5, 'am']],
    {'s1': ['fri-pm'], 's2': ['fri', 'mon-eve'], 's3': ['fri-pm', 'sun-am', 'mon-eve']}],
   [['s3', 'PHYS110', 2]])],
 [('regression: weekday names 1', [[['s1', 'A', 0]], [[0, 'am']], {'s1': ['sun']}], []),
  ('regression variant: weekday names 2',
   [[['s2', 'ECON150', 5]], [[1, 'pm'], [2, 'eve'], [4, 'pm'], [4, 'am'], [1, 'eve'], [1, 'eve']],
    {'s1': ['sat', 'fri-pm', 'fri'], 's2': ['mon-eve'], 's3': ['fri-pm', 'mon-eve', 'fri-eve']}],
   []),
  ('partial repair guard 3',
   [[['s3', 'PHYS110', 2], ['s2', 'MATH101', 1], ['s3', 'PHYS110', 5], ['s1', 'MATH101H', 1],
     ['s2', 'CHEM120', 5], ['s1', 'MATH101', 0]],
    [[4, 'eve'], [4, 'pm'], [0, 'pm'], [2, 'eve'], [0, 'am'], [4, 'pm']],
    {'s1': ['sun-am', 'mon-eve'], 's2': ['sat', 'mon-eve'], 's3': ['sun-am']}],
   []),
  ('boundary control 4', [[['s1', 'A', 0]], [[5, 'am']], {'s1': ['sat', 'fri-pm']}], [['s1', 'A', 0]]),
  ('normal control 5',
   [[['s1', 'ECON150', 5], ['s1', 'HIST140', 0], ['s3', 'CHEM120', 2], ['s1', 'HIST140', 4],
     ['s3', 'ECON150', 2]],
    [[2, 'eve'], [5, 'pm'], [6, 'pm'], [6, 'eve'], [1, 'am'], [0, 'am']],
    {'s1': ['sat'], 's2': ['fri', 'fri-eve', 'sat']}],
   []),
  ('normal control 6',
   [[['s2', 'MATH101H', 2], ['s1', 'ECON150', 1], ['s1', 'ECON150', 2]],
    [[3, 'eve'], [5, 'am'], [2, 'am'], [2, 'pm'], [4, 'am'], [2, 'pm']],
    {'s1': ['fri', 'sat'], 's2': ['fri-eve', 'sun-am', 'fri'], 's3': ['fri', 'sun-am', 'mon-eve']}],
   [['s1', 'ECON150', 1]]),
  ('normal control 7',
   [[['s1', 'CHEM120', 5], ['s3', 'CHEM120', 4], ['s2', 'CHEM120', 4], ['s1', 'PHYS110', 4]],
    [[5, 'eve'], [3, 'am'], [6, 'am'], [5, 'am'], [1, 'am'], [3, 'pm']],
    {'s1': ['fri'], 's2': ['mon-eve', 'fri-eve']}],
   []),
  ('normal control 8',
   [[['s2', 'MATH101H', 5], ['s1', 'BIO130', 1], ['s3', 'MATH101', 3], ['s3', 'ECON150', 1],
     ['s3', 'PHYS110', 1]],
    [[1, 'pm'], [5, 'am'], [6, 'eve'], [5, 'eve'], [3, 'am'], [5, 'pm']], {'s3': ['fri-pm']}],
   [])],
 [('regression: weekday names 1',
   [[['s2', 'PHYS110', 4], ['s3', 'BIO130', 3], ['s1', 'CHEM120', 1], ['s1', 'HIST140', 5],
     ['s3', 'HIST140', 3], ['s3', 'HIST140', 5]],
    [[5, 'eve'], [3, 'eve'], [1, 'eve'], [6, 'eve'], [0, 'am'], [5, 'am']],
    {'s1': ['mon-eve', 'sat'], 's2': ['fri-pm'], 's3': ['mon-eve', 'sun-am']}],
   [['s1', 'HIST140', 5], ['s3', 'BIO130', 3], ['s3', 'HIST140', 3]]),
  ('regression variant: weekday names 2',
   [[['s3', 'MATH101', 1], ['s2', 'PHYS110', 0], ['s2', 'MATH101H', 4], ['s1', 'HIST140', 4],
     ['s3', 'BIO130', 1], ['s1', 'ECON150', 5]],
    [[4, 'eve'], [5, 'pm'], [1, 'am'], [1, 'pm'], [5, 'am'], [0, 'pm']],
    {'s1': ['fri-eve'], 's2': ['sun-am', 'fri', 'mon-eve'], 's3': ['mon-eve', 'fri-eve', 'fri-pm']}],
   [['s2', 'PHYS110', 0]]),
  ('partial repair guard 3',
   [[['s1', 'PHYS110', 2], ['s3', 'HIST140', 0], ['s3', 'PHYS110', 1]],
    [[0, 'pm'], [5, 'pm'], [4, 'eve'], [6, 'am'], [6, 'am'], [0, 'pm']],
    {'s1': ['sun-am', 'fri'], 's2': ['fri-pm', 'sun-am', 'fri-eve']}],
   [['s1', 'PHYS110', 2]]),
  ('boundary control 4', [[['s1', 'A', 0]], [[4, 'eve']], {'s1': ['fri-pm']}], [['s1', 'A', 0]]),
  ('normal control 5',
   [[['s1', 'MATH101H', 3], ['s3', 'MATH101H', 4], ['s2', 'CHEM120', 1]],
    [[2, 'eve'], [4, 'pm'], [6, 'pm'], [2, 'eve'], [2, 'am'], [0, 'eve']], {'s3': ['fri-eve']}],
   []),
  ('normal control 6',
   [[['s2', 'PHYS110', 4], ['s1', 'ECON150', 0], ['s2', 'ECON150', 2], ['s3', 'PHYS110', 4],
     ['s2', 'HIST140', 0]],
    [[3, 'pm'], [0, 'pm'], [5, 'pm'], [1, 'pm'], [1, 'pm'], [4, 'am']],
    {'s1': ['fri', 'mon-eve', 'fri-pm'], 's2': ['sat'], 's3': ['sat', 'fri', 'sun-am']}],
   [['s2', 'ECON150', 2]]),
  ('normal control 7',
   [[['s2', 'MATH101H', 0], ['s1', 'CHEM120', 4], ['s1', 'HIST140', 2], ['s2', 'BIO130', 3]],
    [[4, 'am'], [3, 'pm'], [6, 'eve'], [3, 'pm'], [4, 'pm'], [4, 'pm']],
    {'s1': ['fri-pm'], 's2': ['fri'], 's3': ['fri-pm', 'mon-eve', 'sun-am']}],
   [['s1', 'CHEM120', 4], ['s2', 'MATH101H', 0]]),
  ('normal control 8',
   [[['s1', 'BIO130', 3]], [[5, 'am'], [5, 'am'], [0, 'am'], [1, 'pm'], [3, 'am'], [6, 'am']],
    {'s2': ['sun-am', 'sat', 'mon-eve'], 's3': ['sat', 'sun-am']}],
   [])]]
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: weekday names 1	`[]`	`[['s1', 'A', 0]]`	Failed
regression variant: weekday names 2	`[['s3', 'MATH101', 0]]`	`[['s3', 'MATH101', 1]]`	Failed
partial repair guard 3	`[['s3', 'MATH101', 0]]`	`[]`	Failed
boundary control 4	`[]`	`[['s1', 'A', 0]]`	Failed
normal control 5	`[['s1', 'CHEM120', 1]]`	`[['s1', 'BIO130', 4], ['s1', 'CHEM120', 3], ['s1', 'HIST140', 0]]`	Failed
normal control 6	`[]`	`[]`	Passed
normal control 7	`[]`	`[]`	Passed
normal control 8	`[]`	`[['s1', 'BIO130', 0], ['s1', 'ECON150', 1]]`	Failed

SHA-256 / 3e026fe664e40339ab058076206d1274f3492548cf6dad85c07a4b02f221cd2a

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

Stipulated toy exam-timetabling rule set for a bounded model; it does not claim conformance with any institution's regulations or a benchmark specification, and it performs no search or optimisation. 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 2026-09-29T14:52:06.948927+00:00.

Case digest / ed5474569f11b454c940e3d99087081110b81a02efd0496f631a4323eb142abc