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.
Pointwise cdf convergence at a jump is not required
Statement refuted
Weak convergence does not require CDF convergence at a jump of the limiting CDF. For , the witness is , with on the real line.
Facts & Assumptions
Weak convergence of borel probability measures: For Borel probability measures on a metric space S, write if for every bounded continuous real function f on S. Continuity is def-metric-continuity. Such f is Borel measurable (inverse images of open sets are open) and , so the integrals are finite in def-integrable-real-and-complex-functions-and-their-integrals. No completeness or coupling is required.
Cumulative distribution function of a real random variable: Let be a real random variable. Its cumulative distribution function is the function
The second expression is the same quantity written in terms of the law def-law-or-distribution-of-a-random-element of .
Counterexample
Given: The objects, hypotheses and definitions in the statement. Its conclusions are to be established below.
On take and , . This is a probability space: in any disjoint family at most one event is nonempty. For every integer set and . Each map is measurable because every Borel preimage is either or . Its law is respectively or : a Borel set has probability one exactly when it contains the specified value. Define and using F2.
For a point mass, for bounded measurable : this holds for simple functions by the definition of their integral, and then for nonnegative bounded functions by increasing simple approximation, and for real bounded functions by their positive and negative parts. For bounded continuous , continuity at zero therefore gives . By F1 the laws converge weakly.
By F2 and step 1.1, and . Thus for every while . Moreover for every , so has a jump from its left limit zero to its value one at zero. Hence weak convergence does not force CDF convergence at this jump.
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
7 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, §3.2.1, continuity-point convention (standard reference, not scraped)