Alphabeta Math
DefinitionDefinition: Literature-sourcedProof: Not applicablejudge pass (deepseek-v4-pro + gpt-5.6-terra)audited 2026-08-21
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, sigma-finite, and semifinite measures

Definition

Let (X,A,μ) be a measure space (Measure spaces).

  • The measure μ is finite if μ(X)<+∞.
  • It is sigma-finite if there is a sequence (En)n∈N in A such that X=⋃nEn and μ(En)<+∞ for every n.
  • It is semifinite if, whenever E∈A and μ(E)>0, there is F∈A with F⊆E and 0<μ(F)<+∞.

The last condition is automatic when 0<μ(E)<+∞, by taking F=E; its substantive case is μ(E)=+∞.

Depends on

Used by

Dependency tree · two levels

11 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