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.
On a finite vertex set the graph notions agree, and on connected graphs the two path distances agree
Statement
On a finite vertex set the simple-graph, walk, path, cycle, connectedness and component notions on this page agree with the published finite-graph notions. If the graph is connected, its path metric agrees with the published graph distance; more generally, the same equality holds after restricting to any connected component.
Facts & Assumptions
Given: The hypotheses of the Statement.
A simple graph is a pair with any set and a set of two-element subsets of (Simple graphs on an arbitrary vertex set).
A walk of length in a simple graph is a finite vertex list with consecutive vertices adjacent; a path is a walk with distinct vertices; the graph is connected when it is nonempty and every two vertices are joined by a path (Walks, paths, connectedness and components in a simple graph on an arbitrary vertex set).
A walk of length is a finite vertex list (Walks, closed walks, trails, paths and cycles, with length equal to the number of traversed edges).
Vertices and of a graph are connected, or reachable from one another, when a path in has endpoints and . Equivalently, a walk joins them, because turns such a walk into a path. (Connected graphs and connected components defined by the existence of vertex paths).
For vertices in one connected component, the published graph distance is the least length of a path joining them (Graph distance within a component, eccentricity, diameter and girth, including the acyclic convention).
These are the metric axioms, so shortest-path distance is a metric on . (Shortest-path distance is a metric on every connected component).
By deleting zero or more closed segments from its vertex list, one obtains a path from to of length at most . If repeats a vertex, the resulting path can be chosen to have length strictly less than . (Every walk between two vertices contains a path between the same endpoints).
The path metric of a connected simple graph assigns to two vertices the least length of a path joining them (The path metric of a connected simple graph).
The path metric of a connected simple graph is a metric on its vertex set (The path metric of a connected simple graph is a metric on its vertex set).
Every walk in a simple graph contains a path with the same endpoints and of no greater length (Every walk contains a path between the same endpoints, of no greater length).
Proof
A simple graph whose vertex set is finite is a finite simple graph in the published sense, clause by clause.
The walk, path, cycle, connectedness and component notions defined here read verbatim as the published ones on a finite vertex set, and the walk-to-path lemma specialises to the published one.
The published graph distance is the least length of a path in the same sense. It therefore agrees with the path metric when the graph is connected and, for a disconnected graph, with the path metric of each connected component. The metric statement specialises to the published component-wise one.
Depends on
- Simple graphs on an arbitrary vertex set
- Walks, paths, connectedness and components in a simple graph on an arbitrary vertex set
- Every walk contains a path between the same endpoints, of no greater length
- The path metric of a connected simple graph
- The path metric of a connected simple graph is a metric on its vertex set
- A finite simple graph is a finite vertex set together with a set of two-element vertex subsets
- Walks, closed walks, trails, paths and cycles, with length equal to the number of traversed edges
- Connected graphs and connected components defined by the existence of vertex paths
- Graph distance within a component, eccentricity, diameter and girth, including the acyclic convention
- Shortest-path distance is a metric on every connected component
- Every walk between two vertices contains a path between the same endpoints
Used by
Dependency tree · two levels
17 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
- C. Loh, Geometric Group Theory: An Introduction (2015 course version), 264 pp. (standard reference, not scraped)
- C. Drutu and M. Kapovich, Geometric Group Theory (with an appendix by B. Nica), 837 pp. (standard reference, not scraped)