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FA-50711 / Raster clipping / Open access

Layer clip isolation: end erases parent · case 01

Resolving a child replaces previously drawn parent samples.

Verified by executionVariant 1 · 16 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Resolving a child replaces previously drawn parent samples.

VERIFIED REPAIR

Apply the documented state transition at end erases parent. A layer captures the parent clip and starts with its own full local clip. Child drawing accumulates coverage in that layer; layer completion intersects child coverage with the saved parent clip. Discard removes the layer without publishing. A layer-local clear erases only its accumulated coverage. Parent clip edits after opening cannot change the captured parent clip.

Unsuccessful approach: Applying the parent clip to already drawn parent samples retroactively removes earlier content.

Case contract

A layer captures the parent clip and starts with its own full local clip. Child drawing accumulates coverage in that layer; layer completion intersects child coverage with the saved parent clip. Discard removes the layer without publishing. A layer-local clear erases only its accumulated coverage. Parent clip edits after opening cannot change the captured parent clip.

Why this case matters

Raster clip state can leak coverage across draws even when every individual region is valid.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(commands, size):
    full=set(range(size))
    clip=set(full)
    coverage=set()
    stack=[]
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='clip': clip &= set(cmd[1])
        elif op=='replace': clip=set(cmd[1]) & full
        elif op=='begin':
            stack.append((set(clip),set(coverage)))
            clip=set(full)
            coverage=set()
        elif op=='draw': coverage |= set(cmd[1]) & clip
        elif op=='clear': coverage.clear()
        elif op=='end' and stack:
            parent_clip,parent_coverage=stack.pop()
            coverage=coverage & parent_clip
            clip=parent_clip
        elif op=='discard' and stack: clip,coverage=stack.pop()
        elif op=='inspect': out.append(sorted(coverage))
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 4), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 4), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 4), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 4), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 4), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 4), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 4), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 4), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 4), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 4), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 4), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 4), [[0, 1, 2, 3]])
if N == 2:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 5), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 5), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 5), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 5), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 5), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 5), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 5), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 5), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 5), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 5), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 5), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 5), [[0, 1, 2, 3, 4]])
if N == 3:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 6), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 6), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 6), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 6), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 6), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 6), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 6), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 6), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 6), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 6), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 6), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 6), [[0, 1, 2, 3, 4, 5]])
if N == 4:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 7), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 7), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 7), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 7), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 7), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 7), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 7), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 7), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 7), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 7), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 7), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 7), [[0, 1, 2, 3, 4, 5, 6]])
if N == 5:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 8), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 8), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 8), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 8), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 8), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 8), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 8), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 8), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 8), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 8), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 8), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 8), [[0, 1, 2, 3, 4, 5, 6, 7]])
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 fixtureActualExpectedOutcome
explicit sequence 0[[1], []][[1], []]Passed
explicit sequence 1[[]][[]]Passed
explicit sequence 2[[0, 1]][[0, 1]]Passed
explicit sequence 3[[1]][[1]]Passed
explicit sequence 4[[1]][[1]]Passed
explicit sequence 5[[0]][[0]]Passed
explicit sequence 6[[1]][[0, 1]]Failed
explicit sequence 7[[]][[]]Passed
explicit sequence 8[[0]][[0]]Passed
explicit sequence 9[[1], [1]][[1], [0, 1]]Failed
explicit sequence 10[[0, 1]][[0, 1]]Passed
explicit sequence 11[[]][[]]Passed
explicit sequence 12[[0]][[0]]Passed
explicit sequence 13[[1]][[0, 1]]Failed
explicit sequence 14[[]][[]]Passed
explicit sequence 15[[0, 1, 2, 3]][[0, 1, 2, 3]]Passed

SHA-256 / a36f4bd92ac497a5b14cc5e5a0cd96886d459b2ac0caf90d33dd82ffd2c7b01a

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(commands, size):
    full=set(range(size))
    clip=set(full)
    coverage=set()
    stack=[]
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='clip': clip &= set(cmd[1])
        elif op=='replace': clip=set(cmd[1]) & full
        elif op=='begin':
            stack.append((set(clip),set(coverage)))
            clip=set(full)
            coverage=set()
        elif op=='draw': coverage |= set(cmd[1]) & clip
        elif op=='clear': coverage.clear()
        elif op=='end' and stack:
            parent_clip,parent_coverage=stack.pop()
            coverage=(parent_coverage | coverage) & parent_clip
            clip=parent_clip
        elif op=='discard' and stack: clip,coverage=stack.pop()
        elif op=='inspect': out.append(sorted(coverage))
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 4), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 4), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 4), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 4), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 4), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 4), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 4), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 4), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 4), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 4), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 4), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 4), [[0, 1, 2, 3]])
if N == 2:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 5), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 5), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 5), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 5), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 5), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 5), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 5), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 5), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 5), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 5), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 5), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 5), [[0, 1, 2, 3, 4]])
if N == 3:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 6), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 6), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 6), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 6), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 6), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 6), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 6), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 6), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 6), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 6), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 6), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 6), [[0, 1, 2, 3, 4, 5]])
if N == 4:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 7), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 7), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 7), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 7), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 7), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 7), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 7), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 7), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 7), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 7), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 7), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 7), [[0, 1, 2, 3, 4, 5, 6]])
if N == 5:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 8), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 8), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 8), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 8), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 8), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 8), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 8), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 8), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 8), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 8), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 8), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 8), [[0, 1, 2, 3, 4, 5, 6, 7]])
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 fixtureActualExpectedOutcome
explicit sequence 0[[1], []][[1], []]Passed
explicit sequence 1[[]][[]]Passed
explicit sequence 2[[0, 1]][[0, 1]]Passed
explicit sequence 3[[1]][[1]]Passed
explicit sequence 4[[1]][[1]]Passed
explicit sequence 5[[0]][[0]]Passed
explicit sequence 6[[0, 1]][[0, 1]]Passed
explicit sequence 7[[]][[]]Passed
explicit sequence 8[[0]][[0]]Passed
explicit sequence 9[[1], [0, 1]][[1], [0, 1]]Passed
explicit sequence 10[[0, 1]][[0, 1]]Passed
explicit sequence 11[[]][[]]Passed
explicit sequence 12[[0]][[0]]Passed
explicit sequence 13[[1]][[0, 1]]Failed
explicit sequence 14[[]][[]]Passed
explicit sequence 15[[0, 1, 2, 3]][[0, 1, 2, 3]]Passed

SHA-256 / 658b1447c96ed5fd25d968038703ecf304b8262709ec5a9680073241f7edf790

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(commands, size):
    full=set(range(size))
    clip=set(full)
    coverage=set()
    stack=[]
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='clip': clip &= set(cmd[1])
        elif op=='replace': clip=set(cmd[1]) & full
        elif op=='begin':
            stack.append((set(clip),set(coverage)))
            clip=set(full)
            coverage=set()
        elif op=='draw': coverage |= set(cmd[1]) & clip
        elif op=='clear': coverage.clear()
        elif op=='end' and stack:
            parent_clip,parent_coverage=stack.pop()
            coverage=parent_coverage | (coverage & parent_clip)
            clip=parent_clip
        elif op=='discard' and stack: clip,coverage=stack.pop()
        elif op=='inspect': out.append(sorted(coverage))
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 4), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 4), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 4), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 4), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 4), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 4), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 4), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 4), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 4), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 4), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 4), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 4), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 4), [[0, 1, 2, 3]])
if N == 2:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 5), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 5), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 5), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 5), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 5), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 5), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 5), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 5), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 5), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 5), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 5), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 5), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 5), [[0, 1, 2, 3, 4]])
if N == 3:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 6), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 6), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 6), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 6), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 6), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 6), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 6), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 6), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 6), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 6), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 6), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 6), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 6), [[0, 1, 2, 3, 4, 5]])
if N == 4:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 7), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 7), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 7), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 7), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 7), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 7), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 7), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 7), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 7), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 7), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 7), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 7), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 7), [[0, 1, 2, 3, 4, 5, 6]])
if N == 5:
    check('explicit sequence 0', solve([['replace', [0]], ['begin'], ['draw', [1]], ['inspect'], ['end'], ['inspect']], 8), [[1], []])
    check('explicit sequence 1', solve([['draw', [0]], ['begin'], ['inspect']], 8), [[]])
    check('explicit sequence 2', solve([['begin'], ['draw', [0]], ['draw', [1]], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 3', solve([['begin'], ['replace', [1]], ['draw', [0, 1]], ['inspect']], 8), [[1]])
    check('explicit sequence 4', solve([['begin'], ['draw', [0]], ['clear'], ['draw', [1]], ['inspect']], 8), [[1]])
    check('explicit sequence 5', solve([['replace', [0]], ['begin'], ['draw', [0, 1]], ['end'], ['inspect']], 8), [[0]])
    check('explicit sequence 6', solve([['draw', [0]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 7', solve([['replace', [0]], ['begin'], ['end'], ['draw', [1]], ['inspect']], 8), [[]])
    check('explicit sequence 8', solve([['draw', [0]], ['begin'], ['draw', [1]], ['discard'], ['inspect']], 8), [[0]])
    check('explicit sequence 9', solve([['replace', [0, 1]], ['draw', [0]], ['begin'], ['replace', [1]], ['begin'], ['draw', [1, 2]], ['end'], ['inspect'], ['end'], ['inspect']], 8), [[1], [0, 1]])
    check('explicit sequence 10', solve([['draw', [0]], ['draw', [0, 1]], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 11', solve([['replace', []], ['draw', [0]], ['inspect']], 8), [[]])
    check('explicit sequence 12', solve([['replace', [0]], ['draw', [0]], ['clear'], ['draw', [0, 1]], ['inspect']], 8), [[0]])
    check('explicit sequence 13', solve([['draw', [0]], ['replace', [1]], ['begin'], ['draw', [1]], ['end'], ['inspect']], 8), [[0, 1]])
    check('explicit sequence 14', solve([['replace', []], ['begin'], ['end'], ['draw', [1]], ['inspect']], 8), [[]])
    check('explicit sequence 15', solve([['draw', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['inspect']], 8), [[0, 1, 2, 3, 4, 5, 6, 7]])
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 fixtureActualExpectedOutcome
explicit sequence 0[[1], []][[1], []]Passed
explicit sequence 1[[]][[]]Passed
explicit sequence 2[[0, 1]][[0, 1]]Passed
explicit sequence 3[[1]][[1]]Passed
explicit sequence 4[[1]][[1]]Passed
explicit sequence 5[[0]][[0]]Passed
explicit sequence 6[[0, 1]][[0, 1]]Passed
explicit sequence 7[[]][[]]Passed
explicit sequence 8[[0]][[0]]Passed
explicit sequence 9[[1], [0, 1]][[1], [0, 1]]Passed
explicit sequence 10[[0, 1]][[0, 1]]Passed
explicit sequence 11[[]][[]]Passed
explicit sequence 12[[0]][[0]]Passed
explicit sequence 13[[0, 1]][[0, 1]]Passed
explicit sequence 14[[]][[]]Passed
explicit sequence 15[[0, 1, 2, 3]][[0, 1, 2, 3]]Passed

SHA-256 / 1b6f65e20cc6dbf91741ea768362eaae0bb4ba64d585538d65c37a73e5df185a

Verification & scope

Finite one-dimensional integer sample sets model coverage state only; no geometric intersection, memory layout, GPU or graphics-standard conformance is claimed. 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 2026-09-29T14:45:11.798791+00:00.

Case digest / 8cbc03afdd2d94ad1883c65d444dac41f750fa92ea05fb532c936afc10d07084