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.
Borel measurable and Lebesgue measurable functions on
Definition
Assume the Axiom of Countable Choice (The Axiom of Countable Choice ()), so Assuming countable choice, is a sigma-algebra containing every elementary set and is a complete measure extending elementary volume makes a sigma-algebra. Let with .
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A function is Borel measurable when it is measurable as a map
in the sense of A measurable function between measurable spaces.
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A function is Lebesgue measurable when it is measurable as a map
where is the Lebesgue sigma-algebra of Lebesgue measurable sets, the family , and the restricted set function .
When , these are the corresponding notions for real-valued functions.
Depends on
The Borel sigma-algebra of a topological space
Lebesgue measurable sets, the family , and the restricted set function
A measurable function between measurable spaces
Assuming countable choice, is a sigma-algebra containing every elementary set and is a complete measure extending elementary volume
The Axiom of Countable Choice ()