Alphabeta Math
LemmaStatement: AI-generatedProof: AI-generated
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.

Finite maximal extension of a 2-connected subgraph

Statement

Every 2-connected subgraph of a finite simple graph is contained in a maximal 2-connected subgraph, hence in a nontrivial block.

Facts & Assumptions

[F1]

A finite simple graph has finite vertex and edge sets, and its subgraphs are specified by subsets of these sets. A finite simple graph is a finite vertex set together with a set of two-element vertex subsets Subgraphs, induced subgraphs and spanning subgraphs

[F2]

A maximal 2-connected subgraph is a nontrivial block; maximality is with respect to subgraph containment. Cutvertices, 2-connected pieces and nontrivial blocks

Proof

Given: The graphs and hypotheses in the Statement.

Goal: The asserted conclusion.

1.1F1

Let H be the given 2-connected subgraph. There are finitely many subgraphs of the ambient graph, so the nonempty family of 2-connected subgraphs containing H is finite. Choose one maximizing the sum of its vertex and edge counts.

2.1F1F2step 1.1∎

A proper supergraph in that family would strictly increase that sum. There is therefore no larger 2-connected subgraph containing the chosen one, and it is a nontrivial block containing H.

Depends on

Used by · 2

Dependency tree · 2 levels

Each result is drawn at its shortest distance from this item. Arrows run from prerequisites to the items that use them; this item has a heavier outline. External source nodes link directly to the cited text. The view shows up to two dependency steps; open a prerequisite to continue.