FA-11746 / Localization message semantics / Open access

Last-digit plural rules misclassify teen quantities · case 01

Last-digit plural rules misclassify teen quantities.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

A final-digit lookup ignores the final-two-digit teen exclusion.

VERIFIED REPAIR

For a nonnegative integer, choose one for last digit 1 except final two digits 11; few for last digits 2..4 except final two digits 12..14; many otherwise.

Unsuccessful approach: Special-casing 11 alone leaves 12 through 14 in the few branch.

Case contract

For a nonnegative integer, choose one for last digit 1 except final two digits 11; few for last digits 2..4 except final two digits 12..14; many otherwise.

Why this case matters

This offline controlled message model isolates a localization decision; it does not implement a complete message-format or locale standard.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(n):
    return 'one' if n % 10 == 1 else ('few' if n % 10 in (2,3,4) else 'many')
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('one', solve(100*N+1), 'one')
check('eleven', solve(100*N+11), 'many')
check('twelve', solve(100*N+12), 'many')
check('fourteen', solve(100*N+14), 'many')
check('few', solve(100*N+4), 'few')
check('zero', solve(0), 'many')
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
one	`one`	`one`	Passed
eleven	`one`	`many`	Failed
twelve	`few`	`many`	Failed
fourteen	`few`	`many`	Failed
few	`few`	`few`	Passed
zero	`many`	`many`	Passed

SHA-256 / 8ef22b2a936e9a8b9cdcddebc109325d4979d753432e3a863ee0a2b615122bf9

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(n):
    return 'many' if n % 100 == 11 else ('one' if n % 10 == 1 else ('few' if n % 10 in (2,3,4) else 'many'))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('one', solve(100*N+1), 'one')
check('eleven', solve(100*N+11), 'many')
check('twelve', solve(100*N+12), 'many')
check('fourteen', solve(100*N+14), 'many')
check('few', solve(100*N+4), 'few')
check('zero', solve(0), 'many')
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
one	`one`	`one`	Passed
eleven	`many`	`many`	Passed
twelve	`few`	`many`	Failed
fourteen	`few`	`many`	Failed
few	`few`	`few`	Passed
zero	`many`	`many`	Passed

SHA-256 / e4de8c72d0c0e6e1b165df0c5936ad7d6340a8c8553d2a1fa49e1b010b48aa41

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(n):
    return 'one' if n % 10 == 1 and n % 100 != 11 else ('few' if n % 10 in (2,3,4) and n % 100 not in (12,13,14) else 'many')
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('one', solve(100*N+1), 'one')
check('eleven', solve(100*N+11), 'many')
check('twelve', solve(100*N+12), 'many')
check('fourteen', solve(100*N+14), 'many')
check('few', solve(100*N+4), 'few')
check('zero', solve(0), 'many')
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
one	`one`	`one`	Passed
eleven	`many`	`many`	Passed
twelve	`many`	`many`	Passed
fourteen	`many`	`many`	Passed
few	`few`	`few`	Passed
zero	`many`	`many`	Passed

SHA-256 / d4dcddb77af84f3b4d29d0bcd7b258541b41c56964cccfec2da4882410d181de

Verification & scope

Only the explicitly specified miniature locale/message rules are modeled. 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 2026-09-29T14:38:50.556503+00:00.

Case digest / 0d8e584826a2580362cf39429f5882ddc65b86f3d2d6ed498d98d214972acc76