Alphabeta Math
PropositionStatement: Literature-sourcedProof: AI-adaptedprecheck 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.

Every isometry is a bilipschitz equivalence and every bilipschitz equivalence is a quasi-isometry, and two metrics on one set are Lipschitz equivalent exactly when the identity is a bilipschitz equivalence between them

Statement

Every isometry is a bilipschitz equivalence and every bilipschitz equivalence is a quasi-isometry, and two metrics on one set are Lipschitz equivalent exactly when the identity is a bilipschitz equivalence between them.

Facts & Assumptions

Given: The hypotheses of the Statement.

[F1]

A map is a bilipschitz embedding when c−1d(x,x′)≤d(f(x),f(x′))≤c d(x,x′) for some c>0, and a bilipschitz equivalence when it is a bijective such map with bilipschitz inverse (Bilipschitz embeddings and bilipschitz equivalences of metric spaces).

[L1]

A map is (L,C)-coarse Lipschitz when d(f(x),f(x′))≤L d(x,x′)+C, and an (L,C)-quasi-isometric embedding when in addition L−1d(x,x′)−C≤d(f(x),f(x′)) (Coarse Lipschitz maps and quasi-isometric embeddings).

[L2]

A subset is coarsely dense when every point of the space is within a fixed distance of it, and a quasi-isometry is a coarse Lipschitz map admitting a coarse Lipschitz quasi-inverse (Coarsely dense subsets, quasi-inverses and quasi-isometries).

[L3]

Isometric embedding and isometry. A function f:X→Y is an isometric embedding if (Isometry, isometric embedding, and the subspace metric on a subset).

[L4]
  • d and d′ are topologically equivalent if they have the same metric topology: Td=Td′. - d and d′ are uniformly equivalent if for every real ε>0 there are reals δ>0 and δ′>0 such that, for all x,y∈X, d(x,y)<δ  ⟹  d′(x,y)<εandd′(x,y)<δ′  ⟹  d(x,y)<ε. - d and d′ are Lipschitz equivalent if there are reals α,β>0 with α d(x,y)  ≤  d′(x,y)  ≤  β d(x,y)for all x,y∈X. (Topologically, uniformly and Lipschitz equivalent metrics on a set).
[L5]

If d and d′ are Lipschitz equivalent, they are uniformly equivalent. (Lipschitz equivalence implies uniform equivalence implies topological equivalence).

Proof

technique · direct
1.1F1L3

An isometry is a bilipschitz equivalence with multiplicative constant one.

2.1F1L1L2step 1.1

If f:X→Y is a bilipschitz equivalence, then f and f−1 are both coarse Lipschitz with additive constant zero, and the composites are the identities; hence f is a quasi-isometry.

3.1F1L4L5step 2.1∎

Two metrics on one set are Lipschitz equivalent exactly when the identity between them is a bilipschitz equivalence; this is a comparison of two definitions written on the same data.

Depends on

Used by

Dependency tree · two levels

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Sources