FA-99646 / Chunk citation alignment / Open access

Global citation offsets are sliced without rebasing · case 01

Global citation offsets are sliced without rebasing.

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

ROOT CAUSE

The chunk prefix remains in coordinates local to the full document.

THE FAILURE

The chunk prefix remains in coordinates local to the full document.

Unsuccessful approach: Clamping negatives to zero hides a citation that begins before the chunk.

Case contract

Given chunk start b and global half-open span [s,e), return local [s-b,e-b), even if endpoints are negative.

Why this case matters

A deterministic citation bookkeeping model isolates source attribution from rendering and retrieval.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(base, span):
    s,e=span
    return [s,e]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('inside',solve(N,[N+2,N+5]),[2,5])
check('before chunk',solve(N,[N-2,N+1]),[-2,1])
check('zero base',solve(0,[0,3]),[0,3])
check('empty',solve(N,[N+4,N+4]),[4,4])
check('later interval',solve(2,[9,12]),[7,10])
check('negative base',solve(-2,[1,3]),[3,5])
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
inside	`[3, 6]`	`[2, 5]`	Failed
before chunk	`[-1, 2]`	`[-2, 1]`	Failed
zero base	`[0, 3]`	`[0, 3]`	Passed
empty	`[5, 5]`	`[4, 4]`	Failed
later interval	`[9, 12]`	`[7, 10]`	Failed
negative base	`[1, 3]`	`[3, 5]`	Failed

SHA-256 / c61bf66f72152a0ec75f49077a939408c2ad6ac4b1351f61b0acbab133e02791

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(base, span):
    s,e=span
    return [max(0,s-base),max(0,e-base)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('inside',solve(N,[N+2,N+5]),[2,5])
check('before chunk',solve(N,[N-2,N+1]),[-2,1])
check('zero base',solve(0,[0,3]),[0,3])
check('empty',solve(N,[N+4,N+4]),[4,4])
check('later interval',solve(2,[9,12]),[7,10])
check('negative base',solve(-2,[1,3]),[3,5])
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
inside	`[2, 5]`	`[2, 5]`	Passed
before chunk	`[0, 1]`	`[-2, 1]`	Failed
zero base	`[0, 3]`	`[0, 3]`	Passed
empty	`[4, 4]`	`[4, 4]`	Passed
later interval	`[7, 10]`	`[7, 10]`	Passed
negative base	`[3, 5]`	`[3, 5]`	Passed

SHA-256 / 5b3322f3ae8fc2dc342af2c2d04f7134536d0b3f292a31199809a89bbd889b40

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 6 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

Inputs are small integer offsets and identifiers under the stated toy contract; this does not define a document format or production citation API. 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 2026-09-30T16:48:26.712580+00:00.

Case digest / 950f660b466b19cfb61807521dc73e2196b86ff72f2f34ca2a5e0758da1b2b10