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.
Tightness extracts a weakly convergent subsequence
Statement
Assume AC. A tight sequence of Borel probability laws on a Polish S has a subsequence converging weakly to a Borel probability on that same S.
Facts & Assumptions
Prokhorov tightness theorem on polish spaces: Assume AC. A family of Borel probabilities on a Polish space S is tight if and only if it is relatively sequentially compact for weak convergence.
Proof
Given: The objects, hypotheses and definitions in the statement. Its conclusions are to be established below.
Let . The given uniform compact bounds are exactly tightness of this family. The forward implication of F1 makes it relatively sequentially compact.
Apply that property to the original sequence itself. It supplies increasing indices and a Borel probability on S with . In particular the limit has mass one and lies on S, as asserted.
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
13 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
- Durrett, §§2.4–2.5, pp. 76–87 (standard reference, not scraped)