Alphabeta Math
ExampleConstruction: Literature-sourcedVerification: AI-generatedSession-authored (Fable 5 assisted)precheck passaudited 2026-08-27
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.

Closed surface groups are hyperbolic

Example

The fundamental group of a closed hyperbolic surface is a hyperbolic group.

Facts & Assumptions

Given: A closed hyperbolic surface Σ and its fundamental group π1(Σ).

[L1]

The hyperbolic plane is hyperbolic (The hyperbolic plane is hyperbolic).

[L2]

The Švarc-Milnor lemma transfers geometric actions on proper geodesic spaces to quasi-isometries with finitely generated groups (The Svarc-Milnor lemma).

[L3]

Hyperbolicity is invariant under quasi-isometry (Hyperbolicity is a quasi-isometry invariant of geodesic spaces).

Verification

technique · direct
1.1

The group π1(Σ) acts properly discontinuously and cocompactly by deck transformations on the universal cover H2 of Σ.

given
2.1

By [L2], π1(Σ) is quasi-isometric to H2, and [L1] shows that H2 is hyperbolic. Therefore [L3] makes π1(Σ) hyperbolic.

L1L2L3step 1.1

Depends on

Used by

Nothing in the library uses this result yet.

Dependency tree · two levels

14 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