Problem packetWorkR348
[#R348] Every caterpillar is graceful
claim. Rosa's zig-zag labeling gives a graceful labeling, in fact an alpha-labeling, for every caterpillar.
1Summary
Walk the spine and assign labels alternately from the low end and the high end of the available range. The construction is explicit and gives an alpha-labeling, which is why caterpillars compose so freely in later constructions. The exhaustive sweep through n=15 in this project is consistent with it: no caterpillar appears among the trees found to have no alpha-labeling.
Supported evidence. Recorded scope: caterpillars, of any size.
2Evidence
A verification source is cited. This record has no executable replay attached.
Verification source: www.combinatorics.org ↗, Gallian, Dynamic Survey of Graph Labeling, Rosa 1967
3How it connects
Supports
- problem
Used by
- attempt
Recorded for
- problem
4Agent packet
A compact handoff with the evidence boundary, replay manifest, and relation pointers.
View structured packet
{
"schema": "theoremdb-agent-record-v1",
"ref": "R348",
"content_hash": null,
"slug": "gtc-claim-caterpillars",
"type": "claim",
"title": "Every caterpillar is graceful",
"summary": "Rosa's zig-zag labeling gives a graceful labeling, in fact an alpha-labeling, for every caterpillar.",
"relevance": "For Graceful tree conjecture, record gtc-claim-caterpillars (“Every caterpillar is graceful”) records a bound, answer, status fact, or structural consequence. The record states: Rosa's zig-zag labeling gives a graceful labeling, in fact an alpha-labeling, for every caterpillar.",
"relevance_source": "recorded",
"body": "Walk the spine and assign labels alternately from the low end and the high end of the available range. The construction is explicit and gives an alpha-labeling, which is why caterpillars compose so freely in later constructions. The exhaustive sweep through n=15 in this project is consistent with it: no caterpillar appears among the trees found to have no alpha-labeling.",
"status": "established",
"evidence_grade": "sourced",
"scope": {
"kind": "family",
"statement": "caterpillars, of any size",
"family": "caterpillars"
},
"reproduction": {
"schema": "theoremdb-reproduction-v1",
"readiness": "source_only",
"kind": "claim",
"citation": {
"url": "https://www.combinatorics.org/ojs/index.php/eljc/article/view/DS6",
"locator": "Gallian, Dynamic Survey of Graph Labeling, Rosa 1967"
},
"missing": [
"source",
"command",
"runtime",
"expected_output"
]
},
"formal_statement": null,
"source": {
"url": "https://www.combinatorics.org/ojs/index.php/eljc/article/view/DS6",
"locator": "Gallian, Dynamic Survey of Graph Labeling, Rosa 1967"
},
"models": [],
"relations": [
{
"slug": "graceful-tree-conjecture",
"title": "Graceful tree conjecture",
"object_type": "problem",
"relation": "supports",
"direction": "outgoing"
},
{
"slug": "R345",
"title": "Extend the caterpillar construction to lobsters",
"object_type": "attempt",
"relation": "uses",
"direction": "incoming"
},
{
"slug": "graceful-tree-conjecture",
"title": "graceful tree conjecture",
"object_type": "problem",
"relation": "recorded_for",
"direction": "outgoing"
}
]
}5Provenance
View source, identifiers, and projection details
- Project
- graceful-tree-conjecture
- Locator
- Gallian, Dynamic Survey of Graph Labeling, Rosa 1967
- License
- CC-BY-4.0
- Contributors
- Philip Weiss, TheoremDB graceful-tree reproduction
- Source
- www.combinatorics.org ↗
- Public record
- R348
- Stable alias
- gtc-claim-caterpillars
- Projection
- Reproduction fields are derived from the immutable record.
A statement this project treats as settled at the recorded evidence grade, with the work that backs it.