Nazi-Era Red Flag Date Range Overlap Checker
Flag documentary intervals overlapping caller declared historical review window using half-open years and union exposure; named Nazi-era review does not itself establish theft, restitution eligibility or clear provenance.
Description
Ownership documentation may overlap a historical review window.
Ownership documentation may overlap a historical review window. Union exposure prevents repeated documents from double-counting years.
Flag documentary intervals overlapping caller declared historical review window using half-open years and union exposure; named Nazi-era review does not itself establish theft, restitution eligibility or clear provenance.
When to use Nazi-Era Red Flag Date Range Overlap Checker
Use this tool to flag documentary intervals overlapping caller declared historical review window using half-open years and union exposure; named Nazi-era review does not itself establish theft, restitution eligibility or clear provenance.
Prepare the collection, exposure, scheduling or financial records required for this calculation. Keep row order and the declared units consistent.
How to use Nazi-Era Red Flag Date Range Overlap Checker and understand its results
- Prepare the collection, exposure, scheduling or financial records required for this calculation. Keep row order and the declared units consistent.
- Enter objectOwnershipYearIntervals, callerHistoricalReviewYearBounds using the field table and calculation rules, then run the tool.
- Read historicalReviewOverlapYearsByInterval, overlappingIntervalIndices, unionHistoricalOverlapYears. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| objectOwnershipYearIntervals | Object ownership year intervals | list of list of number | Required |
| callerHistoricalReviewYearBounds | Caller historical review year bounds | list of number | Required |
Supply a positive-duration review pair and ordered ownership interval pairs. Treat years as half-open, return local overlap lengths and zero-based positive-overlap indices, then union clipped intervals for total years. Endpoint-only touches have zero overlap.1
overlap = max(0,min(interval end,review end) − max(interval start,review start)) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| historicalReviewOverlapYearsByInterval | Historical review overlap years by interval | list of number |
| overlappingIntervalIndices | Overlapping interval indices | list of number |
| unionHistoricalOverlapYears | Union historical overlap years | number |
{
"input": {
"objectOwnershipYearIntervals": [
[
1920,
1930
],
[
1940,
1950
]
],
"callerHistoricalReviewYearBounds": [
1933,
1946
]
},
"output": {
"historicalReviewOverlapYearsByInterval": [
0,
6
],
"overlappingIntervalIndices": [
1
],
"unionHistoricalOverlapYears": 6
}
}Limitations and assumptions
A review flag does not establish theft, restitution rights or clear provenance.
Numbers and computed results must be finite; overflow produces an error. Matrices are limited to 128 rows and 128 entries per row; other numeric lists are limited to 100,000 entries. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Provenance Gap Year Span Calculator: Union overlapping documented ownership intervals and retain all gaps inside caller half-open review years; unlike event-date spacing, overlapping documentation is not double-counted and gaps are not proof of unlawful ownership. For a complementary task, use Deaccession Justification Criteria Checklist Completeness Checker: Audit deaccession documentation against caller required/blocking criteria while retaining missing evidence; completeness is not ethical/legal authorization to dispose of collection objects.
References
Similar or alternative tools
- Provenance Gap Year Span Calculator
Union overlapping documented ownership intervals and retain all gaps inside caller half-open review years; unlike event-date spacing, overlapping documentation is not double-counted and gaps are not proof of unlawful ownership.
- Deaccession Justification Criteria Checklist Completeness Checker
Audit deaccession documentation against caller required/blocking criteria while retaining missing evidence; completeness is not ethical/legal authorization to dispose of collection objects.