FA-62921 / Insurance premium rating / Open access

Short-rate cancellation return premium: Minimum earned premium is applied to insurer cancellations · case 01

Early insurer-initiated cancellations retain a minimum earned premium.

Verified by executionVariant 1 · 10 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The minimum earned cap was moved out of the insured branch.

VERIFIED REPAIR

Apply the minimum earned premium only when the insured cancels.

Unsuccessful approach: Halving the minimum for insurer cancellations still withholds premium the insurer must return.

Case contract

Input premium, term_days, days_in_force d, initiator, min_earned_permille. d<0 or term<=0 -> 'invalid'; d>=term -> 0; d==0 (flat cancel) returns the full premium. Otherwise unearned = premium*(term-d)/term; the insurer returns it in full; an insured cancellation returns 90% of unearned but never more than premium minus the minimum earned premium. Round half-up once.

Why this case matters

Premium rating engines apply ordered tabular rules where one misplaced boundary or step silently misprices policies.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(x):
    p=x['premium']; t=x['term_days']; d=x['days_in_force']
    if d<0 or t<=0: return 'invalid'
    if d>=t: return 0
    if d==0: return p
    unearned=Fraction(p*(t-d),t)
    if x['initiator']=='insured':
        ret=unearned*Fraction(90,100)
    else:
        ret=unearned
    ret=min(ret,p-Fraction(p*x['min_earned_permille'],1000))
    return math.floor(ret+Fraction(1,2))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['insured cancels mid-term', {'premium': 167157, 'term_days': 365, 'days_in_force': 113, 'initiator': 'insured', 'min_earned_permille': 100}, 103866], ['insurer cancels mid-term', {'premium': 107827, 'term_days': 365, 'days_in_force': 285, 'initiator': 'insurer', 'min_earned_permille': 250}, 23633], ['insurer cancel early with minimum on file', {'premium': 135423, 'term_days': 365, 'days_in_force': 32, 'initiator': 'insurer', 'min_earned_permille': 400}, 123550], ['insured minimum earned binds', {'premium': 102264, 'term_days': 365, 'days_in_force': 24, 'initiator': 'insured', 'min_earned_permille': 300}, 71585], ['flat cancel by insured', {'premium': 246750, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 250}, 246750], ['flat cancel by insurer', {'premium': 77604, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 77604], ['one day in force', {'premium': 285647, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 284060], ['expiry day', {'premium': 163861, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 253298, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 250}, 'invalid'], ['six month policy insured cancel', {'premium': 169415, 'term_days': 182, 'days_in_force': 105, 'initiator': 'insured', 'min_earned_permille': 100}, 64508]], [['insured cancels mid-term', {'premium': 136580, 'term_days': 365, 'days_in_force': 120, 'initiator': 'insured', 'min_earned_permille': 100}, 82509], ['insurer cancels mid-term', {'premium': 142197, 'term_days': 365, 'days_in_force': 42, 'initiator': 'insurer', 'min_earned_permille': 100}, 125835], ['insurer cancel early with minimum on file', {'premium': 130516, 'term_days': 365, 'days_in_force': 22, 'initiator': 'insurer', 'min_earned_permille': 400}, 122649], ['insured minimum earned binds', {'premium': 155356, 'term_days': 365, 'days_in_force': 30, 'initiator': 'insured', 'min_earned_permille': 300}, 108749], ['flat cancel by insured', {'premium': 128340, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 250}, 128340], ['flat cancel by insurer', {'premium': 205493, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 250}, 205493], ['one day in force', {'premium': 125332, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 124636], ['expiry day', {'premium': 149858, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 143435, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 250}, 'invalid'], ['six month policy insured cancel', {'premium': 219606, 'term_days': 182, 'days_in_force': 115, 'initiator': 'insured', 'min_earned_permille': 100}, 72760]], [['insured cancels mid-term', {'premium': 236883, 'term_days': 365, 'days_in_force': 198, 'initiator': 'insured', 'min_earned_permille': 100}, 97544], ['insurer cancels mid-term', {'premium': 224272, 'term_days': 365, 'days_in_force': 89, 'initiator': 'insurer', 'min_earned_permille': 100}, 169586], ['insurer cancel early with minimum on file', {'premium': 271417, 'term_days': 365, 'days_in_force': 21, 'initiator': 'insurer', 'min_earned_permille': 400}, 255801], ['insured minimum earned binds', {'premium': 236806, 'term_days': 365, 'days_in_force': 27, 'initiator': 'insured', 'min_earned_permille': 300}, 165764], ['flat cancel by insured', {'premium': 50665, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 50665], ['flat cancel by insurer', {'premium': 266999, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 250}, 266999], ['one day in force', {'premium': 51282, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 250}, 50997], ['expiry day', {'premium': 202320, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 67184, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 241675, 'term_days': 182, 'days_in_force': 118, 'initiator': 'insured', 'min_earned_permille': 100}, 76486]], [['insured cancels mid-term', {'premium': 82503, 'term_days': 365, 'days_in_force': 154, 'initiator': 'insured', 'min_earned_permille': 100}, 42924], ['insurer cancels mid-term', {'premium': 137193, 'term_days': 365, 'days_in_force': 295, 'initiator': 'insurer', 'min_earned_permille': 100}, 26311], ['insurer cancel early with minimum on file', {'premium': 157674, 'term_days': 365, 'days_in_force': 15, 'initiator': 'insurer', 'min_earned_permille': 400}, 151194], ['insured minimum earned binds', {'premium': 283617, 'term_days': 365, 'days_in_force': 21, 'initiator': 'insured', 'min_earned_permille': 300}, 198532], ['flat cancel by insured', {'premium': 97666, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 97666], ['flat cancel by insurer', {'premium': 137018, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 137018], ['one day in force', {'premium': 261346, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 259894], ['expiry day', {'premium': 135749, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 260111, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 289415, 'term_days': 182, 'days_in_force': 81, 'initiator': 'insured', 'min_earned_permille': 100}, 144548]], [['insured cancels mid-term', {'premium': 59284, 'term_days': 365, 'days_in_force': 188, 'initiator': 'insured', 'min_earned_permille': 100}, 25874], ['insurer cancels mid-term', {'premium': 88844, 'term_days': 365, 'days_in_force': 105, 'initiator': 'insurer', 'min_earned_permille': 100}, 63286], ['insurer cancel early with minimum on file', {'premium': 70835, 'term_days': 365, 'days_in_force': 24, 'initiator': 'insurer', 'min_earned_permille': 400}, 66177], ['insured minimum earned binds', {'premium': 148105, 'term_days': 365, 'days_in_force': 29, 'initiator': 'insured', 'min_earned_permille': 300}, 103674], ['flat cancel by insured', {'premium': 267217, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 267217], ['flat cancel by insurer', {'premium': 201088, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 201088], ['one day in force', {'premium': 293778, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 250}, 292146], ['expiry day', {'premium': 81772, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 193452, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 273407, 'term_days': 182, 'days_in_force': 107, 'initiator': 'insured', 'min_earned_permille': 100}, 101401]]]
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
insured cancels mid-term	`103866`	`103866`	Passed
insurer cancels mid-term	`23633`	`23633`	Passed
insurer cancel early with minimum on file	`81254`	`123550`	Failed
insured minimum earned binds	`71585`	`71585`	Passed
flat cancel by insured	`246750`	`246750`	Passed
flat cancel by insurer	`77604`	`77604`	Passed
one day in force	`257082`	`284060`	Failed
expiry day	`0`	`0`	Passed
negative days rejected	`invalid`	`invalid`	Passed
six month policy insured cancel	`64508`	`64508`	Passed

SHA-256 / fc237235b213045c953795a5763f40b40184fa9e09318b62ad1b468724b099d5

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(x):
    p=x['premium']; t=x['term_days']; d=x['days_in_force']
    if d<0 or t<=0: return 'invalid'
    if d>=t: return 0
    if d==0: return p
    unearned=Fraction(p*(t-d),t)
    if x['initiator']=='insured':
        ret=unearned*Fraction(90,100)
        ret=min(ret,p-Fraction(p*x['min_earned_permille'],1000))
    else:
        ret=min(unearned,p-Fraction(p*x['min_earned_permille'],2000))
    return math.floor(ret+Fraction(1,2))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['insured cancels mid-term', {'premium': 167157, 'term_days': 365, 'days_in_force': 113, 'initiator': 'insured', 'min_earned_permille': 100}, 103866], ['insurer cancels mid-term', {'premium': 107827, 'term_days': 365, 'days_in_force': 285, 'initiator': 'insurer', 'min_earned_permille': 250}, 23633], ['insurer cancel early with minimum on file', {'premium': 135423, 'term_days': 365, 'days_in_force': 32, 'initiator': 'insurer', 'min_earned_permille': 400}, 123550], ['insured minimum earned binds', {'premium': 102264, 'term_days': 365, 'days_in_force': 24, 'initiator': 'insured', 'min_earned_permille': 300}, 71585], ['flat cancel by insured', {'premium': 246750, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 250}, 246750], ['flat cancel by insurer', {'premium': 77604, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 77604], ['one day in force', {'premium': 285647, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 284060], ['expiry day', {'premium': 163861, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 253298, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 250}, 'invalid'], ['six month policy insured cancel', {'premium': 169415, 'term_days': 182, 'days_in_force': 105, 'initiator': 'insured', 'min_earned_permille': 100}, 64508]], [['insured cancels mid-term', {'premium': 136580, 'term_days': 365, 'days_in_force': 120, 'initiator': 'insured', 'min_earned_permille': 100}, 82509], ['insurer cancels mid-term', {'premium': 142197, 'term_days': 365, 'days_in_force': 42, 'initiator': 'insurer', 'min_earned_permille': 100}, 125835], ['insurer cancel early with minimum on file', {'premium': 130516, 'term_days': 365, 'days_in_force': 22, 'initiator': 'insurer', 'min_earned_permille': 400}, 122649], ['insured minimum earned binds', {'premium': 155356, 'term_days': 365, 'days_in_force': 30, 'initiator': 'insured', 'min_earned_permille': 300}, 108749], ['flat cancel by insured', {'premium': 128340, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 250}, 128340], ['flat cancel by insurer', {'premium': 205493, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 250}, 205493], ['one day in force', {'premium': 125332, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 124636], ['expiry day', {'premium': 149858, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 143435, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 250}, 'invalid'], ['six month policy insured cancel', {'premium': 219606, 'term_days': 182, 'days_in_force': 115, 'initiator': 'insured', 'min_earned_permille': 100}, 72760]], [['insured cancels mid-term', {'premium': 236883, 'term_days': 365, 'days_in_force': 198, 'initiator': 'insured', 'min_earned_permille': 100}, 97544], ['insurer cancels mid-term', {'premium': 224272, 'term_days': 365, 'days_in_force': 89, 'initiator': 'insurer', 'min_earned_permille': 100}, 169586], ['insurer cancel early with minimum on file', {'premium': 271417, 'term_days': 365, 'days_in_force': 21, 'initiator': 'insurer', 'min_earned_permille': 400}, 255801], ['insured minimum earned binds', {'premium': 236806, 'term_days': 365, 'days_in_force': 27, 'initiator': 'insured', 'min_earned_permille': 300}, 165764], ['flat cancel by insured', {'premium': 50665, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 50665], ['flat cancel by insurer', {'premium': 266999, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 250}, 266999], ['one day in force', {'premium': 51282, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 250}, 50997], ['expiry day', {'premium': 202320, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 67184, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 241675, 'term_days': 182, 'days_in_force': 118, 'initiator': 'insured', 'min_earned_permille': 100}, 76486]], [['insured cancels mid-term', {'premium': 82503, 'term_days': 365, 'days_in_force': 154, 'initiator': 'insured', 'min_earned_permille': 100}, 42924], ['insurer cancels mid-term', {'premium': 137193, 'term_days': 365, 'days_in_force': 295, 'initiator': 'insurer', 'min_earned_permille': 100}, 26311], ['insurer cancel early with minimum on file', {'premium': 157674, 'term_days': 365, 'days_in_force': 15, 'initiator': 'insurer', 'min_earned_permille': 400}, 151194], ['insured minimum earned binds', {'premium': 283617, 'term_days': 365, 'days_in_force': 21, 'initiator': 'insured', 'min_earned_permille': 300}, 198532], ['flat cancel by insured', {'premium': 97666, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 97666], ['flat cancel by insurer', {'premium': 137018, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 137018], ['one day in force', {'premium': 261346, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 259894], ['expiry day', {'premium': 135749, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 260111, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 289415, 'term_days': 182, 'days_in_force': 81, 'initiator': 'insured', 'min_earned_permille': 100}, 144548]], [['insured cancels mid-term', {'premium': 59284, 'term_days': 365, 'days_in_force': 188, 'initiator': 'insured', 'min_earned_permille': 100}, 25874], ['insurer cancels mid-term', {'premium': 88844, 'term_days': 365, 'days_in_force': 105, 'initiator': 'insurer', 'min_earned_permille': 100}, 63286], ['insurer cancel early with minimum on file', {'premium': 70835, 'term_days': 365, 'days_in_force': 24, 'initiator': 'insurer', 'min_earned_permille': 400}, 66177], ['insured minimum earned binds', {'premium': 148105, 'term_days': 365, 'days_in_force': 29, 'initiator': 'insured', 'min_earned_permille': 300}, 103674], ['flat cancel by insured', {'premium': 267217, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 267217], ['flat cancel by insurer', {'premium': 201088, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 201088], ['one day in force', {'premium': 293778, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 250}, 292146], ['expiry day', {'premium': 81772, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 193452, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 273407, 'term_days': 182, 'days_in_force': 107, 'initiator': 'insured', 'min_earned_permille': 100}, 101401]]]
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
insured cancels mid-term	`103866`	`103866`	Passed
insurer cancels mid-term	`23633`	`23633`	Passed
insurer cancel early with minimum on file	`108338`	`123550`	Failed
insured minimum earned binds	`71585`	`71585`	Passed
flat cancel by insured	`246750`	`246750`	Passed
flat cancel by insurer	`77604`	`77604`	Passed
one day in force	`271365`	`284060`	Failed
expiry day	`0`	`0`	Passed
negative days rejected	`invalid`	`invalid`	Passed
six month policy insured cancel	`64508`	`64508`	Passed

SHA-256 / 1ea8d8251c0289d6f936bd7c3869f953351fabc2969f29a2fe48289c13fe8581

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(x):
    p=x['premium']; t=x['term_days']; d=x['days_in_force']
    if d<0 or t<=0: return 'invalid'
    if d>=t: return 0
    if d==0: return p
    unearned=Fraction(p*(t-d),t)
    if x['initiator']=='insured':
        ret=unearned*Fraction(90,100)
        ret=min(ret,p-Fraction(p*x['min_earned_permille'],1000))
    else:
        ret=unearned
    return math.floor(ret+Fraction(1,2))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['insured cancels mid-term', {'premium': 167157, 'term_days': 365, 'days_in_force': 113, 'initiator': 'insured', 'min_earned_permille': 100}, 103866], ['insurer cancels mid-term', {'premium': 107827, 'term_days': 365, 'days_in_force': 285, 'initiator': 'insurer', 'min_earned_permille': 250}, 23633], ['insurer cancel early with minimum on file', {'premium': 135423, 'term_days': 365, 'days_in_force': 32, 'initiator': 'insurer', 'min_earned_permille': 400}, 123550], ['insured minimum earned binds', {'premium': 102264, 'term_days': 365, 'days_in_force': 24, 'initiator': 'insured', 'min_earned_permille': 300}, 71585], ['flat cancel by insured', {'premium': 246750, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 250}, 246750], ['flat cancel by insurer', {'premium': 77604, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 77604], ['one day in force', {'premium': 285647, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 284060], ['expiry day', {'premium': 163861, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 253298, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 250}, 'invalid'], ['six month policy insured cancel', {'premium': 169415, 'term_days': 182, 'days_in_force': 105, 'initiator': 'insured', 'min_earned_permille': 100}, 64508]], [['insured cancels mid-term', {'premium': 136580, 'term_days': 365, 'days_in_force': 120, 'initiator': 'insured', 'min_earned_permille': 100}, 82509], ['insurer cancels mid-term', {'premium': 142197, 'term_days': 365, 'days_in_force': 42, 'initiator': 'insurer', 'min_earned_permille': 100}, 125835], ['insurer cancel early with minimum on file', {'premium': 130516, 'term_days': 365, 'days_in_force': 22, 'initiator': 'insurer', 'min_earned_permille': 400}, 122649], ['insured minimum earned binds', {'premium': 155356, 'term_days': 365, 'days_in_force': 30, 'initiator': 'insured', 'min_earned_permille': 300}, 108749], ['flat cancel by insured', {'premium': 128340, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 250}, 128340], ['flat cancel by insurer', {'premium': 205493, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 250}, 205493], ['one day in force', {'premium': 125332, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 124636], ['expiry day', {'premium': 149858, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 143435, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 250}, 'invalid'], ['six month policy insured cancel', {'premium': 219606, 'term_days': 182, 'days_in_force': 115, 'initiator': 'insured', 'min_earned_permille': 100}, 72760]], [['insured cancels mid-term', {'premium': 236883, 'term_days': 365, 'days_in_force': 198, 'initiator': 'insured', 'min_earned_permille': 100}, 97544], ['insurer cancels mid-term', {'premium': 224272, 'term_days': 365, 'days_in_force': 89, 'initiator': 'insurer', 'min_earned_permille': 100}, 169586], ['insurer cancel early with minimum on file', {'premium': 271417, 'term_days': 365, 'days_in_force': 21, 'initiator': 'insurer', 'min_earned_permille': 400}, 255801], ['insured minimum earned binds', {'premium': 236806, 'term_days': 365, 'days_in_force': 27, 'initiator': 'insured', 'min_earned_permille': 300}, 165764], ['flat cancel by insured', {'premium': 50665, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 50665], ['flat cancel by insurer', {'premium': 266999, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 250}, 266999], ['one day in force', {'premium': 51282, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 250}, 50997], ['expiry day', {'premium': 202320, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 67184, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 241675, 'term_days': 182, 'days_in_force': 118, 'initiator': 'insured', 'min_earned_permille': 100}, 76486]], [['insured cancels mid-term', {'premium': 82503, 'term_days': 365, 'days_in_force': 154, 'initiator': 'insured', 'min_earned_permille': 100}, 42924], ['insurer cancels mid-term', {'premium': 137193, 'term_days': 365, 'days_in_force': 295, 'initiator': 'insurer', 'min_earned_permille': 100}, 26311], ['insurer cancel early with minimum on file', {'premium': 157674, 'term_days': 365, 'days_in_force': 15, 'initiator': 'insurer', 'min_earned_permille': 400}, 151194], ['insured minimum earned binds', {'premium': 283617, 'term_days': 365, 'days_in_force': 21, 'initiator': 'insured', 'min_earned_permille': 300}, 198532], ['flat cancel by insured', {'premium': 97666, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 97666], ['flat cancel by insurer', {'premium': 137018, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 137018], ['one day in force', {'premium': 261346, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 100}, 259894], ['expiry day', {'premium': 135749, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 260111, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 289415, 'term_days': 182, 'days_in_force': 81, 'initiator': 'insured', 'min_earned_permille': 100}, 144548]], [['insured cancels mid-term', {'premium': 59284, 'term_days': 365, 'days_in_force': 188, 'initiator': 'insured', 'min_earned_permille': 100}, 25874], ['insurer cancels mid-term', {'premium': 88844, 'term_days': 365, 'days_in_force': 105, 'initiator': 'insurer', 'min_earned_permille': 100}, 63286], ['insurer cancel early with minimum on file', {'premium': 70835, 'term_days': 365, 'days_in_force': 24, 'initiator': 'insurer', 'min_earned_permille': 400}, 66177], ['insured minimum earned binds', {'premium': 148105, 'term_days': 365, 'days_in_force': 29, 'initiator': 'insured', 'min_earned_permille': 300}, 103674], ['flat cancel by insured', {'premium': 267217, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insured', 'min_earned_permille': 100}, 267217], ['flat cancel by insurer', {'premium': 201088, 'term_days': 365, 'days_in_force': 0, 'initiator': 'insurer', 'min_earned_permille': 100}, 201088], ['one day in force', {'premium': 293778, 'term_days': 180, 'days_in_force': 1, 'initiator': 'insurer', 'min_earned_permille': 250}, 292146], ['expiry day', {'premium': 81772, 'term_days': 365, 'days_in_force': 365, 'initiator': 'insured', 'min_earned_permille': 100}, 0], ['negative days rejected', {'premium': 193452, 'term_days': 365, 'days_in_force': -1, 'initiator': 'insured', 'min_earned_permille': 100}, 'invalid'], ['six month policy insured cancel', {'premium': 273407, 'term_days': 182, 'days_in_force': 107, 'initiator': 'insured', 'min_earned_permille': 100}, 101401]]]
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
insured cancels mid-term	`103866`	`103866`	Passed
insurer cancels mid-term	`23633`	`23633`	Passed
insurer cancel early with minimum on file	`123550`	`123550`	Passed
insured minimum earned binds	`71585`	`71585`	Passed
flat cancel by insured	`246750`	`246750`	Passed
flat cancel by insurer	`77604`	`77604`	Passed
one day in force	`284060`	`284060`	Passed
expiry day	`0`	`0`	Passed
negative days rejected	`invalid`	`invalid`	Passed
six month policy insured cancel	`64508`	`64508`	Passed

SHA-256 / 8c6d8f7d5b6d5cb471c05c630920bceb4897fca789049505fe23d6fafbd9ece3

Verification & scope

A deterministic bounded teaching model of a stipulated toy rating contract. Amounts are integer cents and factors exact rationals; it makes no claim of conformance with any filed rating plan, bureau manual or jurisdiction. 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 2026-09-29T14:47:09.428598+00:00.

Case digest / 4e37073c86b33c9c3ec27a4206b63d53ee2b1fc34a5f404c04ce123194ca3ee8