How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
An isolate is excluded from Ncut and reinserted separately
Example
Let with and every other weight zero. For the algorithm inputs, take , , for , and the constant deterministic graph builder defined by for every input tuple. In mode with and row normalization disabled (the default), the positive-degree vertex set is , the active Ncut cluster is with value , and vertex is returned separately as the singleton without entering any Ncut denominator.
Example references
Graph diagram
Vertices and are joined by their unit-weight edge; vertex is isolated. The relative coordinates are only for display.
diagram failed to render:
\begin{tikzpicture}
\node[draw,circle] (v1) at (0,0) {$1$};
\node[draw,circle] (v2) at (1.5,0) {$2$};
\node[draw,circle] (v3) at (4,0) {$3$};
\draw (v1)--node[above] {$1$}(v2);
\end{tikzpicture}Facts & Assumptions
Given: , with and every other weight zero, the data, dimensions, and constant graph builder from the Example (so the computed matrix is exactly ), normalized mode, , and row normalization disabled.
Finite weighted graph Laplacian: , , and .
RatioCut and normalized cut for a finite weighted graph: Ncut sums over a partition of into nonempty parts.
Quadratic form and kernel of a weighted graph Laplacian: the kernel consists of vectors constant on each support component.
Deterministic weighted spectral clustering with explicit isolate and eigenspace conventions: normalized mode uses only positive-degree vertices, chooses the prescribed zero-mode eigenvector first, runs the specified Lloyd updates, and appends isolates as separate singleton outputs.
Verification
The degrees are , so , , and .
The active support graph is connected, so [F3] gives a one-dimensional zero eigenspace spanned by . Its prescribed unit vector is , and it is the single eigenvector used when .
Both embedding rows are . The first and only Lloyd center is the first row; both points receive its label, its mean remains , and the labels and center are unchanged. Thus the active cluster returned is , after which [F4] appends separately.
The active part has cut and volume , so its Ncut value is . Vertex has volume but is not in , so it appears in no Ncut denominator.
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
8 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- Ulrike von Luxburg, A Tutorial on Spectral Clustering, Statistics and Computing 17(4), 2007 (standard reference, not scraped)
- Jean Gallier, Notes on Elementary Spectral Graph Theory: Applications to Graph Clustering Using Normalized Cuts, 2013 (standard reference, not scraped)