Alphabeta Math
DefinitionDefinition: Literature-sourcedProof: Not applicablejudge pass (gpt-5.6-terra)audited 2026-09-14
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.

Approximation property and bounded approximation property

Definition

Let X be a Banach space. It has the approximation property (AP) if for every norm-compact set CX and every ε>0 there is a bounded finite-rank operator T:XX such that

supxCTxx<ε.

Here finite rank means that T(X) is finite-dimensional.

For λ0, X has the λ-bounded approximation property (λ-BAP) if the same assertion holds with the additional operator-norm bound Tλ, where the norm is that of The operator norm as the least bound and as the unit-sphere or unit-ball supremum. It has the bounded approximation property (BAP) if it has λ-BAP for some finite λ.

No sequence of approximating operators is required; this matters in nonseparable spaces. Plainly λ-BAP implies AP.

Depends on

Used by

Dependency tree · two levels

8 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