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.
A finite-population design induces probability laws on observed records
Statement
For every fixed , the set function defined in Finite populations and sampling designs is a probability measure on .
Facts & Assumptions
Given: A finite nonempty population index set , a finite sampling support with positive weights summing to , and a fixed value function .
Finite populations and sampling designs: The observed-record space is , its event family is the full power set, and .
Sigma-algebras: A sigma-algebra is an algebra of subsets closed under countable unions.
Measures on sigma-algebras: A measure assigns zero to the empty set and is countably additive on every pairwise disjoint sequence of measurable sets.
Probability measures and probability spaces: A probability measure is a measure whose total mass is .
Proof
Since is the full power set of , it contains every subset of and is closed under complements and countable unions; hence it is a sigma-algebra by [F2].
For every , the sum defining is finite and nonnegative. It gives and .
Let be pairwise disjoint in and put . The sets are pairwise disjoint and at most of them are nonempty. Their union is , so rearranging these finite weighted sums gives . By [F3], is a measure; by [F4] and step 1.2, its total mass is , so it is a probability measure.
Depends on
Used by
- A zero inclusion probability prevents total identification and universal unbiased estimation Theorem
- The Horvitz–Thompson total and mean are design-unbiased under positive inclusion probabilities Theorem
Cited to discharge well-definedness by Finite populations and sampling designs.
Dependency tree · two levels
16 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
- Shalabh, Sampling Theory, Chapter 2: Simple Random Sampling, IIT Kanpur (standard reference, not scraped)
- John J. Borkowski, Horvitz–Thompson Estimators, STAT 446 Lecture 6, Montana State University (standard reference, not scraped)