Problem packetResearch packetR72
Two diagonals and 64 crosses span, while each vacant outer line is stable
Link to a section
The author supplies a mathematical argument.
Recorded status: established
Recorded scope: the two long diagonals, the 64 row-column crosses, and the four outer lines of the open-boundary 8 by 8 grid
Complete recorded scope and conditions
{
"kind": "bounded",
"statement": "the two long diagonals, the 64 row-column crosses, and the four outer lines of the open-boundary 8 by 8 grid",
"bounds": {
"spanning_base_patterns": {
"min": 66,
"max": 66
},
"stable_vacant_lines": {
"min": 4,
"max": 4
}
},
"exhaustive": true
}Originating problem: Exact spanning-set count for two-neighbor bootstrap percolation on the eight grid
Recorded relationships: The spanning-set count lies between 177,024,301,925,259,284 and 18,161,310,923,858,378,752
Authored record and scope
- Authored title
- Two diagonals and 64 crosses span, while each vacant outer line is stable
- Record type
- claim
- Stored status
- established
- Evidence grade
- mathematical_argument
- Recorded scope data
- { "kind": "bounded", "statement": "the two long diagonals, the 64 row-column crosses, and the four outer lines of the open-boundary 8 by 8 grid", "bounds": { "spanning_base_patterns": { "min": 66, "max": 66 }, "stable_vacant_lines": { "min": 4, "max": 4 } }, "exhaustive": true }
- Linked research record IDs
- R71
2Authored explanation
For the main diagonal, every cell at diagonal distance \(d>0\) has two neighbors at distance \(d-1\). Induction fills the board. Reflection gives the other long diagonal.
If row \(r\) and column \(c\) are initially occupied, a cell away from their union has two neighbors whose coordinate distances to that union are each one step smaller. Induction fills all four rectangular regions. Every superset of any of these 66 patterns therefore spans.
If an outer line is vacant and all other cells are occupied, each vertex of that line has at most one occupied neighbor. The line stays vacant. Removing more initially occupied vertices cannot create a second occupied neighbor, so every initial set disjoint from that line fails to span.
Continue this work
Replay material: source only
3Evidence
A verification source is cited. This record has no executable replay attached.
Verification source: doi.org ↗, Elementary induction and stability argument, replayed on every base pattern by bpe8c-artifact-closure-and-bound-verifier
4What was measured
5How it connects
Supports
Supported by
- artifact
Recorded for
- problem
Cite this record
Cite the original sources separately.
Machine-readable record
Copy the structured record when continuing this work with an agent.
{
"schema": "theoremdb-agent-record-v1",
"ref": "R72",
"content_hash": null,
"slug": "bpe8c-claim-sufficient-and-obstructing-families",
"type": "claim",
"title": "Two diagonals and 64 crosses span, while each vacant outer line is stable",
"summary": "These finite families turn monotonicity into certified lower and upper counts.",
"relevance": "For Exact spanning-set count for two-neighbor bootstrap percolation on the eight grid, record bpe8c-claim-sufficient-and-obstructing-families (“Two diagonals and 64 crosses span, while each vacant outer line is stable”) records a bound, answer, status fact, or structural consequence. The record states: These finite families turn monotonicity into certified lower and upper counts.",
"relevance_source": "recorded",
"body": "For the main diagonal, every cell at diagonal distance \\(d>0\\) has two neighbors at distance \\(d-1\\). Induction fills the board. Reflection gives the other long diagonal.\n\nIf row \\(r\\) and column \\(c\\) are initially occupied, a cell away from their union has two neighbors whose coordinate distances to that union are each one step smaller. Induction fills all four rectangular regions. Every superset of any of these 66 patterns therefore spans.\n\nIf an outer line is vacant and all other cells are occupied, each vertex of that line has at most one occupied neighbor. The line stays vacant. Removing more initially occupied vertices cannot create a second occupied neighbor, so every initial set disjoint from that line fails to span.",
"status": "established",
"evidence_grade": "mathematical_argument",
"scope": {
"kind": "bounded",
"statement": "the two long diagonals, the 64 row-column crosses, and the four outer lines of the open-boundary 8 by 8 grid",
"bounds": {
"spanning_base_patterns": {
"min": 66,
"max": 66
},
"stable_vacant_lines": {
"min": 4,
"max": 4
}
},
"exhaustive": true
},
"reproduction": {
"schema": "theoremdb-reproduction-v1",
"readiness": "source_only",
"kind": "claim",
"citation": {
"url": "https://doi.org/10.1088/0305-4470/21/19/017",
"locator": "Elementary induction and stability argument, replayed on every base pattern by bpe8c-artifact-closure-and-bound-verifier"
},
"missing": [
"source",
"command",
"runtime",
"expected_output"
]
},
"formal_statement": null,
"source": {
"url": "https://doi.org/10.1088/0305-4470/21/19/017",
"locator": "Elementary induction and stability argument, replayed on every base pattern by bpe8c-artifact-closure-and-bound-verifier"
},
"models": [],
"continuation": null,
"relations": [
{
"slug": "R71",
"title": "The spanning-set count lies between 177,024,301,925,259,284 and 18,161,310,923,858,378,752",
"object_type": "claim",
"relation": "supports",
"direction": "outgoing"
},
{
"slug": "R69",
"title": "Deterministic closure verifier and inclusion-exclusion certificate",
"object_type": "artifact",
"relation": "supports",
"direction": "incoming"
},
{
"slug": "bootstrap-percolation-eight-count",
"title": "bootstrap percolation eight count",
"object_type": "problem",
"relation": "recorded_for",
"direction": "outgoing"
}
]
}7Provenance
View source, identifiers, and projection details
A statement this project treats as settled at the recorded evidence grade, with the work that backs it.