Alphabeta Math
LemmaStatement: Literature-sourcedProof: AI-adaptedSession-authored (Fable 5 assisted)precheck passaudited 2026-08-26
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.

[F1]

A simple graph is a pair (V,E) with V any set and E a set of two-element subsets of V (Simple graphs on an arbitrary vertex set).

[F2]

A walk of length in a simple graph is a finite vertex list (v0,,v) 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).

[L1]

E[V]2:={{u,v}V:uv}. (A finite simple graph is a finite vertex set together with a set of two-element vertex subsets).

[L3]

Vertices u and v of a graph G are connected, or reachable from one another, when a path in G has endpoints u and v. 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).

[L4]

For vertices u,v 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).

[L5]

These are the metric axioms, so shortest-path distance is a metric on C. (Shortest-path distance is a metric on every connected component).

[L6]

By deleting zero or more closed segments from its vertex list, one obtains a path from v0 to v of length at most . If W 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).

[L7]

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).

[L8]

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).

[L9]

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

technique · direct
1.1

A simple graph whose vertex set is finite is a finite simple graph in the published sense, clause by clause.

F1L1
2.1

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.

F2L2L3L6L9step 1.1
3.1

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.

L4L5L7L8step 2.1

Depends on

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