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.
The trivial and discrete sigma-algebras are the two extremes
Example
For every set , the trivial sigma-algebra is and the discrete sigma-algebra is . Every sigma-algebra on lies between them under inclusion. If , the two extremes coincide.
Facts & Assumptions
Given: A set .
A sigma-algebra contains the empty set and is closed under complements and countable unions (Sigma-algebras).
Verification
The family satisfies the axioms in [L1]; when , it is the one-member family .
The power set satisfies the axioms in [L1].
Every sigma-algebra contains and hence , and every one is a subfamily of . Thus the two verified families are the extremes, coinciding when .
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
2 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
- R. F. Bass, Real Analysis for Graduate Students, version 5.0, Example 2.2 (standard reference, not scraped)
- T. Tao, An Introduction to Measure Theory, Exercise 1.4.10 (standard reference, not scraped)