FA-100236 / Annotation span alignment / Open access

Serialized end offsets remain exclusive · case 01

Serialized end offsets remain exclusive.

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

ROOT CAUSE

A half-open end is emitted unchanged in a format that requires inclusive end.

THE FAILURE

A half-open end is emitted unchanged in a format that requires inclusive end.

Unsuccessful approach: Subtracting one from every end emits an invalid negative-width record for empty spans.

Case contract

Serialize nonempty half-open spans [start,end) as [start,end-1,label]; omit empty spans.

Why this case matters

A small offline annotation transformation keeps span coordinates explicit when text or token boundaries change.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(spans):
    return [[s,e,l] for s,e,l in spans]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('ordinary span', solve([[0,3,'x']]), [[0,2,'x']])
check('single character', solve([[N,N+1,'y']]), [[N,N,'y']])
check('empty omitted', solve([[2,2,'z']]), [])
check('mixed spans', solve([[1,4,'a'],[5,5,'b'],[7,8,'c']]), [[1,3,'a'],[7,7,'c']])
check('empty list', solve([]), [])
check('negative source coordinates', solve([[-2,0,'q']]), [[-2,-1,'q']])
check('two adjacent spans', solve([[0,1,'a'],[1,2,'b']]), [[0,0,'a'],[1,1,'b']])
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
ordinary span	`[[0, 3, 'x']]`	`[[0, 2, 'x']]`	Failed
single character	`[[1, 2, 'y']]`	`[[1, 1, 'y']]`	Failed
empty omitted	`[[2, 2, 'z']]`	`[]`	Failed
mixed spans	`[[1, 4, 'a'], [5, 5, 'b'], [7, 8, 'c']]`	`[[1, 3, 'a'], [7, 7, 'c']]`	Failed
empty list	`[]`	`[]`	Passed
negative source coordinates	`[[-2, 0, 'q']]`	`[[-2, -1, 'q']]`	Failed
two adjacent spans	`[[0, 1, 'a'], [1, 2, 'b']]`	`[[0, 0, 'a'], [1, 1, 'b']]`	Failed

SHA-256 / 4e310d31231e2520936b8aa99f4822e4b4147100f308b87fb86392ce504538cb

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(spans):
    return [[s,e-1,l] for s,e,l in spans]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('ordinary span', solve([[0,3,'x']]), [[0,2,'x']])
check('single character', solve([[N,N+1,'y']]), [[N,N,'y']])
check('empty omitted', solve([[2,2,'z']]), [])
check('mixed spans', solve([[1,4,'a'],[5,5,'b'],[7,8,'c']]), [[1,3,'a'],[7,7,'c']])
check('empty list', solve([]), [])
check('negative source coordinates', solve([[-2,0,'q']]), [[-2,-1,'q']])
check('two adjacent spans', solve([[0,1,'a'],[1,2,'b']]), [[0,0,'a'],[1,1,'b']])
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
ordinary span	`[[0, 2, 'x']]`	`[[0, 2, 'x']]`	Passed
single character	`[[1, 1, 'y']]`	`[[1, 1, 'y']]`	Passed
empty omitted	`[[2, 1, 'z']]`	`[]`	Failed
mixed spans	`[[1, 3, 'a'], [5, 4, 'b'], [7, 7, 'c']]`	`[[1, 3, 'a'], [7, 7, 'c']]`	Failed
empty list	`[]`	`[]`	Passed
negative source coordinates	`[[-2, -1, 'q']]`	`[[-2, -1, 'q']]`	Passed
two adjacent spans	`[[0, 0, 'a'], [1, 1, 'b']]`	`[[0, 0, 'a'], [1, 1, 'b']]`	Passed

SHA-256 / 50965c457fb4318b54cf36049d707fe44cd87a6f8c6405bd3e3a4aa87b616ef0

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 7 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

Contracts use integer offsets, explicit edits, and supplied token boundaries; they do not define a tokenizer or production annotation format. 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 2026-09-30T16:48:33.127093+00:00.

Case digest / 2a14deb895d23fa9d6c2d95327295cdfe6210d469ce77e49402596af948ca6a2