Understand the failure.
Verify the repair.
Small, reproducible software failures. The broken implementation, the fix that didn’t work, and the one that passed—preserved together.
Explore the cases ↓How results are verified ↗WHAT THE ARCHIVE CONTAINS
100840 executable cases. 20168 are open.
Every case records the implementation that fails, the fix that did not work, and the repair that passed its checks—with recorded outputs and source hashes. This release adds 100840 cases across 20168 failure mechanisms and 254 domains.
The open tier gives you the failure and the unsuccessful fix for one case in every mechanism. The remaining 80672 cases, 5 variants per mechanism, are member-only: the verified repair, its recorded checks, and the full fixture suite are held in the member archive. Read the methodology ↗
A RECORD OF WHAT WENT WRONG
Browse the archive / 100840
Accelerated biweekly schedule: biweekly payment derivation · case 01
Odd-cent monthly payments produce a biweekly payment a half cent short.
Accelerated biweekly schedule: biweekly payment derivation · case 02
Odd-cent monthly payments produce a biweekly payment a half cent short.
Accelerated biweekly schedule: biweekly payment derivation · case 03
Odd-cent monthly payments produce a biweekly payment a half cent short.
Accelerated biweekly schedule: biweekly payment derivation · case 04
Odd-cent monthly payments produce a biweekly payment a half cent short.
Accelerated biweekly schedule: biweekly payment derivation · case 05
Odd-cent monthly payments produce a biweekly payment a half cent short.
Accelerated biweekly schedule: biweekly periodic rate · case 01
Biweekly interest is computed as if there were 24 periods a year.
Accelerated biweekly schedule: biweekly periodic rate · case 02
Biweekly interest is computed as if there were 24 periods a year.
Accelerated biweekly schedule: biweekly periodic rate · case 03
Biweekly interest is computed as if there were 24 periods a year.
Accelerated biweekly schedule: biweekly periodic rate · case 04
Biweekly interest is computed as if there were 24 periods a year.
Accelerated biweekly schedule: biweekly periodic rate · case 05
Biweekly interest is computed as if there were 24 periods a year.
Forbearance capitalization or deferral: payments before forbearance · case 01
The balance entering forbearance reflects a payment the borrower never made.
Forbearance capitalization or deferral: payments before forbearance · case 02
The balance entering forbearance reflects a payment the borrower never made.
Forbearance capitalization or deferral: payments before forbearance · case 03
The balance entering forbearance reflects a payment the borrower never made.
Forbearance capitalization or deferral: payments before forbearance · case 04
The balance entering forbearance reflects a payment the borrower never made.
Forbearance capitalization or deferral: payments before forbearance · case 05
The balance entering forbearance reflects a payment the borrower never made.
Forbearance capitalization or deferral: forbearance accrual compounding · case 01
Forbearance interest compounds monthly.
Forbearance capitalization or deferral: forbearance accrual compounding · case 02
Forbearance interest compounds monthly.
Forbearance capitalization or deferral: forbearance accrual compounding · case 03
Forbearance interest compounds monthly.
Forbearance capitalization or deferral: forbearance accrual compounding · case 04
Forbearance interest compounds monthly.
Forbearance capitalization or deferral: forbearance accrual compounding · case 05
Forbearance interest compounds monthly.
Forbearance capitalization or deferral: extended remaining term · case 01
Capitalized forbearance payments jump because the term was not extended.
Forbearance capitalization or deferral: extended remaining term · case 02
Capitalized forbearance payments jump because the term was not extended.
Forbearance capitalization or deferral: extended remaining term · case 03
Capitalized forbearance payments jump because the term was not extended.
Forbearance capitalization or deferral: extended remaining term · case 04
Capitalized forbearance payments jump because the term was not extended.
Forbearance capitalization or deferral: extended remaining term · case 05
Capitalized forbearance payments jump because the term was not extended.
Forbearance capitalization or deferral: deferral payment · case 01
Deferred forbearance raises the monthly payment.
Forbearance capitalization or deferral: deferral payment · case 02
Deferred forbearance raises the monthly payment.
Forbearance capitalization or deferral: deferral payment · case 03
Deferred forbearance raises the monthly payment.
Forbearance capitalization or deferral: deferral payment · case 04
Deferred forbearance raises the monthly payment.
Forbearance capitalization or deferral: deferral payment · case 05
Deferred forbearance raises the monthly payment.
Forbearance capitalization or deferral: capitalization · case 01
Capitalized forbearance interest never reaches the principal balance.
Forbearance capitalization or deferral: capitalization · case 02
Capitalized forbearance interest never reaches the principal balance.
Forbearance capitalization or deferral: capitalization · case 03
Capitalized forbearance interest never reaches the principal balance.
Forbearance capitalization or deferral: capitalization · case 04
Capitalized forbearance interest never reaches the principal balance.
Forbearance capitalization or deferral: capitalization · case 05
Capitalized forbearance interest never reaches the principal balance.
Mortgage insurance termination: automatic uses scheduled balance · case 01
Automatic termination is triggered early by voluntary prepayments.
Mortgage insurance termination: automatic uses scheduled balance · case 02
Automatic termination is triggered early by voluntary prepayments.
Mortgage insurance termination: automatic uses scheduled balance · case 03
Automatic termination is triggered early by voluntary prepayments.
Mortgage insurance termination: automatic uses scheduled balance · case 04
Automatic termination is triggered early by voluntary prepayments.
Mortgage insurance termination: automatic uses scheduled balance · case 05
Automatic termination is triggered early by voluntary prepayments.
Mortgage insurance termination: automatic threshold · case 01
Insurance drops automatically at the borrower-request threshold.
Mortgage insurance termination: automatic threshold · case 02
Insurance drops automatically at the borrower-request threshold.
Mortgage insurance termination: automatic threshold · case 03
Insurance drops automatically at the borrower-request threshold.
Mortgage insurance termination: automatic threshold · case 04
Insurance drops automatically at the borrower-request threshold.
Mortgage insurance termination: automatic threshold · case 05
Insurance drops automatically at the borrower-request threshold.
Mortgage insurance termination: midpoint month · case 01
Final termination at the midpoint happens a month early.
Mortgage insurance termination: midpoint month · case 02
Final termination at the midpoint happens a month early.
Mortgage insurance termination: midpoint month · case 03
Final termination at the midpoint happens a month early.
Mortgage insurance termination: midpoint month · case 04
Final termination at the midpoint happens a month early.
Mortgage insurance termination: midpoint month · case 05
Final termination at the midpoint happens a month early.
Mortgage insurance termination: midpoint precedence · case 01
Loans that reach 78 percent late keep insurance past the midpoint.
Mortgage insurance termination: midpoint precedence · case 02
Loans that reach 78 percent late keep insurance past the midpoint.
Mortgage insurance termination: midpoint precedence · case 03
Loans that reach 78 percent late keep insurance past the midpoint.
Mortgage insurance termination: midpoint precedence · case 04
Loans that reach 78 percent late keep insurance past the midpoint.
Mortgage insurance termination: midpoint precedence · case 05
Loans that reach 78 percent late keep insurance past the midpoint.
Mortgage insurance termination: request threshold · case 01
Borrowers at exactly 80 percent cannot request cancellation.
Mortgage insurance termination: request threshold · case 02
Borrowers at exactly 80 percent cannot request cancellation.
Mortgage insurance termination: request threshold · case 03
Borrowers at exactly 80 percent cannot request cancellation.
Mortgage insurance termination: request threshold · case 04
Borrowers at exactly 80 percent cannot request cancellation.
Mortgage insurance termination: request threshold · case 05
Borrowers at exactly 80 percent cannot request cancellation.
Installment due date calendar: anchor day drift · case 01
After February every due date sticks to the 28th.
Installment due date calendar: anchor day drift · case 02
After February every due date sticks to the 28th.
Installment due date calendar: anchor day drift · case 03
After February every due date sticks to the 28th.
Installment due date calendar: anchor day drift · case 04
After February every due date sticks to the 28th.
Installment due date calendar: anchor day drift · case 05
After February every due date sticks to the 28th.
Installment due date calendar: year rollover · case 01
Installments after December keep the starting year.
Installment due date calendar: year rollover · case 02
Installments after December keep the starting year.
Installment due date calendar: year rollover · case 03
Installments after December keep the starting year.
Installment due date calendar: year rollover · case 04
Installments after December keep the starting year.
Installment due date calendar: year rollover · case 05
Installments after December keep the starting year.
Installment due date calendar: weekend detection · case 01
Due dates on Saturdays are not rolled.
Installment due date calendar: weekend detection · case 02
Due dates on Saturdays are not rolled.
Installment due date calendar: weekend detection · case 03
Due dates on Saturdays are not rolled.
Installment due date calendar: weekend detection · case 04
Due dates on Saturdays are not rolled.
Installment due date calendar: weekend detection · case 05
Due dates on Saturdays are not rolled.
Installment due date calendar: month boundary test · case 01
Modified-following due dates roll into the next month.
Installment due date calendar: month boundary test · case 02
Modified-following due dates roll into the next month.
Installment due date calendar: month boundary test · case 03
Modified-following due dates roll into the next month.
Installment due date calendar: month boundary test · case 04
Modified-following due dates roll into the next month.
Installment due date calendar: month boundary test · case 05
Modified-following due dates roll into the next month.
Installment due date calendar: no-roll mode · case 01
Loans configured without business-day rolling still move weekend due dates.
Installment due date calendar: no-roll mode · case 02
Loans configured without business-day rolling still move weekend due dates.
Installment due date calendar: no-roll mode · case 03
Loans configured without business-day rolling still move weekend due dates.
Installment due date calendar: no-roll mode · case 04
Loans configured without business-day rolling still move weekend due dates.
Installment due date calendar: no-roll mode · case 05
Loans configured without business-day rolling still move weekend due dates.
Installment due date calendar: holiday rollback · case 01
Modified-following roll-backs land on a holiday.
Installment due date calendar: holiday rollback · case 02
Modified-following roll-backs land on a holiday.
Installment due date calendar: holiday rollback · case 03
Modified-following roll-backs land on a holiday.
Installment due date calendar: holiday rollback · case 04
Modified-following roll-backs land on a holiday.
Installment due date calendar: holiday rollback · case 05
Modified-following roll-backs land on a holiday.
Credit line average daily balance: event effective day · case 01
Draws accrue no interest on the day they are taken.
Credit line average daily balance: event effective day · case 02
Draws accrue no interest on the day they are taken.
Credit line average daily balance: event effective day · case 03
Draws accrue no interest on the day they are taken.
Credit line average daily balance: event effective day · case 04
Draws accrue no interest on the day they are taken.
Credit line average daily balance: event effective day · case 05
Draws accrue no interest on the day they are taken.
Credit line average daily balance: credit balance accrual · case 01
Overpaid lines earn negative interest that offsets later draws.
Credit line average daily balance: credit balance accrual · case 02
Overpaid lines earn negative interest that offsets later draws.
Credit line average daily balance: credit balance accrual · case 03
Overpaid lines earn negative interest that offsets later draws.
Credit line average daily balance: credit balance accrual · case 04
Overpaid lines earn negative interest that offsets later draws.
Credit line average daily balance: credit balance accrual · case 05
Overpaid lines earn negative interest that offsets later draws.
INSPECTABLE BY DESIGN
Every result has a runnable source.
Runnable implementations with recorded outputs, source hashes, and explicit contracts. Related variants share a failure mechanism and belong together in evaluation splits.
Read the methodology ↗