FAILURE MAP
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FA-70446 / GIS polygon topology / Open access

Bounding box topological relation: separation strictness · case 01

Boxes sharing an edge or corner are reported as disjoint.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The separation test uses <=, so boxes that only touch count as separated.

VERIFIED REPAIR

At the separation strictness step restore `a[2] < b[0] or b[2] < a[0] or a[3] < b[1] or b[3] < a[1]`, leaving the rest of the model unchanged.

Unsuccessful approach: The x test was made strict but the y test still treats vertically touching boxes as disjoint.

Case contract

Input [a, b], closed boxes [minx, miny, maxx, maxy] with positive width and height. Return "equals" if identical, else "disjoint" if separated with no shared point, else "contains" if a covers b (shared edges allowed), "within" if b covers a, else "touches" if the boxes share only boundary, else "overlaps".

Why this case matters

Spatial indexes and map tile filters prune candidates with envelope relations before exact geometry tests.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    a, b = x
    if a == b:
        return 'equals'
    if a[2] <= b[0] or b[2] <= a[0] or a[3] <= b[1] or b[3] <= a[1]:
        return 'disjoint'
    if a[0] <= b[0] and a[1] <= b[1] and a[2] >= b[2] and a[3] >= b[3]:
        return 'contains'
    if b[0] <= a[0] and b[1] <= a[1] and b[2] >= a[2] and b[3] >= a[3]:
        return 'within'
    if a[2] == b[0] or b[2] == a[0] or a[3] == b[1] or b[3] == a[1]:
        return 'touches'
    return 'overlaps'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('control #0', [[3, 0, 9, 4], [9, 3, 13, 11]], 'touches'), ('control #1', [[6, 3, 7, 5], [3, 1, 9, 6]], 'within'), ('control #2', [[5, 9, 6, 10], [3, 9, 10, 13]], 'within'), ('control #3', [[8, 2, 9, 4], [1, 10, 4, 15]], 'disjoint'), ('control #4', [[1, 1, 7, 5], [4, 5, 9, 8]], 'touches'), ('control #5', [[9, 7, 16, 13], [1, 10, 7, 13]], 'disjoint'), ('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches')], [('control #3', [[8, 2, 9, 4], [1, 10, 4, 15]], 'disjoint'), ('control #4', [[1, 1, 7, 5], [4, 5, 9, 8]], 'touches'), ('control #5', [[9, 7, 16, 13], [1, 10, 7, 13]], 'disjoint'), ('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches'), ('control #8', [[2, 1, 4, 2], [3, 1, 6, 4]], 'overlaps'), ('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('boundary #17', [[0, 0, 5, 5], [5, 5, 9, 9]], 'touches')], [('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches'), ('control #8', [[2, 1, 4, 2], [3, 1, 6, 4]], 'overlaps'), ('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('control #10', [[7, 1, 10, 3], [7, 0, 14, 3]], 'within'), ('control #11', [[2, 7, 10, 9], [10, 8, 12, 13]], 'touches'), ('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches')], [('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('control #10', [[7, 1, 10, 3], [7, 0, 14, 3]], 'within'), ('control #11', [[2, 7, 10, 9], [10, 8, 12, 13]], 'touches'), ('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('control #13', [[5, 3, 9, 9], [7, 8, 8, 15]], 'overlaps'), ('control #14', [[3, 2, 10, 3], [8, 5, 14, 7]], 'disjoint'), ('control #15', [[3, 5, 7, 12], [9, 2, 16, 3]], 'disjoint'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches')], [('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('control #13', [[5, 3, 9, 9], [7, 8, 8, 15]], 'overlaps'), ('control #14', [[3, 2, 10, 3], [8, 5, 14, 7]], 'disjoint'), ('control #15', [[3, 5, 7, 12], [9, 2, 16, 3]], 'disjoint'), ('boundary #16', [[0, 0, 5, 5], [5, 0, 9, 5]], 'touches'), ('boundary #17', [[0, 0, 5, 5], [5, 5, 9, 9]], 'touches'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches'), ('boundary #26', [[0, 3, 5, 8], [5, 0, 9, 3]], 'touches')]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
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
control #0disjointtouchesFailed
control #1withinwithinPassed
control #2withinwithinPassed
control #3disjointdisjointPassed
control #4disjointtouchesFailed
control #5disjointdisjointPassed
control #6disjointdisjointPassed
control #7disjointtouchesFailed

SHA-256 / 5273ac24c32e510ca85450b42a50e4f1e1964363756230e970a54c404f2b4f39

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    a, b = x
    if a == b:
        return 'equals'
    if a[2] < b[0] or b[2] < a[0] or a[3] <= b[1] or b[3] <= a[1]:
        return 'disjoint'
    if a[0] <= b[0] and a[1] <= b[1] and a[2] >= b[2] and a[3] >= b[3]:
        return 'contains'
    if b[0] <= a[0] and b[1] <= a[1] and b[2] >= a[2] and b[3] >= a[3]:
        return 'within'
    if a[2] == b[0] or b[2] == a[0] or a[3] == b[1] or b[3] == a[1]:
        return 'touches'
    return 'overlaps'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('control #0', [[3, 0, 9, 4], [9, 3, 13, 11]], 'touches'), ('control #1', [[6, 3, 7, 5], [3, 1, 9, 6]], 'within'), ('control #2', [[5, 9, 6, 10], [3, 9, 10, 13]], 'within'), ('control #3', [[8, 2, 9, 4], [1, 10, 4, 15]], 'disjoint'), ('control #4', [[1, 1, 7, 5], [4, 5, 9, 8]], 'touches'), ('control #5', [[9, 7, 16, 13], [1, 10, 7, 13]], 'disjoint'), ('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches')], [('control #3', [[8, 2, 9, 4], [1, 10, 4, 15]], 'disjoint'), ('control #4', [[1, 1, 7, 5], [4, 5, 9, 8]], 'touches'), ('control #5', [[9, 7, 16, 13], [1, 10, 7, 13]], 'disjoint'), ('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches'), ('control #8', [[2, 1, 4, 2], [3, 1, 6, 4]], 'overlaps'), ('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('boundary #17', [[0, 0, 5, 5], [5, 5, 9, 9]], 'touches')], [('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches'), ('control #8', [[2, 1, 4, 2], [3, 1, 6, 4]], 'overlaps'), ('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('control #10', [[7, 1, 10, 3], [7, 0, 14, 3]], 'within'), ('control #11', [[2, 7, 10, 9], [10, 8, 12, 13]], 'touches'), ('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches')], [('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('control #10', [[7, 1, 10, 3], [7, 0, 14, 3]], 'within'), ('control #11', [[2, 7, 10, 9], [10, 8, 12, 13]], 'touches'), ('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('control #13', [[5, 3, 9, 9], [7, 8, 8, 15]], 'overlaps'), ('control #14', [[3, 2, 10, 3], [8, 5, 14, 7]], 'disjoint'), ('control #15', [[3, 5, 7, 12], [9, 2, 16, 3]], 'disjoint'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches')], [('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('control #13', [[5, 3, 9, 9], [7, 8, 8, 15]], 'overlaps'), ('control #14', [[3, 2, 10, 3], [8, 5, 14, 7]], 'disjoint'), ('control #15', [[3, 5, 7, 12], [9, 2, 16, 3]], 'disjoint'), ('boundary #16', [[0, 0, 5, 5], [5, 0, 9, 5]], 'touches'), ('boundary #17', [[0, 0, 5, 5], [5, 5, 9, 9]], 'touches'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches'), ('boundary #26', [[0, 3, 5, 8], [5, 0, 9, 3]], 'touches')]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
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
control #0touchestouchesPassed
control #1withinwithinPassed
control #2withinwithinPassed
control #3disjointdisjointPassed
control #4disjointtouchesFailed
control #5disjointdisjointPassed
control #6disjointdisjointPassed
control #7disjointtouchesFailed

SHA-256 / 56b9a91b65514fdfc2af2a1089e2d801ec2963170500ec909deaf2d4e801634f

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    a, b = x
    if a == b:
        return 'equals'
    if a[2] < b[0] or b[2] < a[0] or a[3] < b[1] or b[3] < a[1]:
        return 'disjoint'
    if a[0] <= b[0] and a[1] <= b[1] and a[2] >= b[2] and a[3] >= b[3]:
        return 'contains'
    if b[0] <= a[0] and b[1] <= a[1] and b[2] >= a[2] and b[3] >= a[3]:
        return 'within'
    if a[2] == b[0] or b[2] == a[0] or a[3] == b[1] or b[3] == a[1]:
        return 'touches'
    return 'overlaps'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('control #0', [[3, 0, 9, 4], [9, 3, 13, 11]], 'touches'), ('control #1', [[6, 3, 7, 5], [3, 1, 9, 6]], 'within'), ('control #2', [[5, 9, 6, 10], [3, 9, 10, 13]], 'within'), ('control #3', [[8, 2, 9, 4], [1, 10, 4, 15]], 'disjoint'), ('control #4', [[1, 1, 7, 5], [4, 5, 9, 8]], 'touches'), ('control #5', [[9, 7, 16, 13], [1, 10, 7, 13]], 'disjoint'), ('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches')], [('control #3', [[8, 2, 9, 4], [1, 10, 4, 15]], 'disjoint'), ('control #4', [[1, 1, 7, 5], [4, 5, 9, 8]], 'touches'), ('control #5', [[9, 7, 16, 13], [1, 10, 7, 13]], 'disjoint'), ('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches'), ('control #8', [[2, 1, 4, 2], [3, 1, 6, 4]], 'overlaps'), ('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('boundary #17', [[0, 0, 5, 5], [5, 5, 9, 9]], 'touches')], [('control #6', [[3, 1, 4, 5], [8, 8, 12, 15]], 'disjoint'), ('control #7', [[1, 7, 6, 11], [0, 6, 7, 7]], 'touches'), ('control #8', [[2, 1, 4, 2], [3, 1, 6, 4]], 'overlaps'), ('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('control #10', [[7, 1, 10, 3], [7, 0, 14, 3]], 'within'), ('control #11', [[2, 7, 10, 9], [10, 8, 12, 13]], 'touches'), ('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches')], [('control #9', [[7, 2, 15, 6], [8, 4, 14, 11]], 'overlaps'), ('control #10', [[7, 1, 10, 3], [7, 0, 14, 3]], 'within'), ('control #11', [[2, 7, 10, 9], [10, 8, 12, 13]], 'touches'), ('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('control #13', [[5, 3, 9, 9], [7, 8, 8, 15]], 'overlaps'), ('control #14', [[3, 2, 10, 3], [8, 5, 14, 7]], 'disjoint'), ('control #15', [[3, 5, 7, 12], [9, 2, 16, 3]], 'disjoint'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches')], [('control #12', [[8, 9, 9, 16], [4, 4, 11, 11]], 'overlaps'), ('control #13', [[5, 3, 9, 9], [7, 8, 8, 15]], 'overlaps'), ('control #14', [[3, 2, 10, 3], [8, 5, 14, 7]], 'disjoint'), ('control #15', [[3, 5, 7, 12], [9, 2, 16, 3]], 'disjoint'), ('boundary #16', [[0, 0, 5, 5], [5, 0, 9, 5]], 'touches'), ('boundary #17', [[0, 0, 5, 5], [5, 5, 9, 9]], 'touches'), ('boundary #18', [[0, 0, 5, 5], [0, 5, 5, 9]], 'touches'), ('boundary #26', [[0, 3, 5, 8], [5, 0, 9, 3]], 'touches')]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
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
control #0touchestouchesPassed
control #1withinwithinPassed
control #2withinwithinPassed
control #3disjointdisjointPassed
control #4touchestouchesPassed
control #5disjointdisjointPassed
control #6disjointdisjointPassed
control #7touchestouchesPassed

SHA-256 / 3f03064c8176ddb89ebf8baacf8a72325c7a0328ab69e3f14df1c6753e2cb46b

Verification & scope

Stipulated deterministic toy contract on a bounded input domain; results are rounded as stated and no conformance with any published standard or library 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 2026-09-29T14:48:20.836045+00:00.

Case digest / cbc2e3636c66cbe6d4caaa523d6e413a0e39b41128ccb99a68f9c5837effae9f