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.
An equicontinuous pointwise-bounded family in has a finite net in the supremum metric
Statement
An equicontinuous pointwise-bounded family is totally bounded for the supremum metric.
Facts & Assumptions
Given: A positive real and an equicontinuous pointwise-bounded family .
Uniform equicontinuity gives a finite set such that agreement within at every point of forces agreement within everywhere (An equicontinuous family on a compact metric space is uniformly equicontinuous).
The family is uniformly bounded (Equicontinuity and pointwise boundedness on a compact metric space imply uniform boundedness).
Totally bounded means that every positive radius admits a finite covering by metric balls (Finite -net and totally bounded metric space).
Proof
Choose a finite -net in from the uniform equicontinuity radius for .
By [L2], every vector lies in one bounded box in ; cover that box by finitely many coordinate cubes of side less than .
Choose one member of from each nonempty inverse image of such a cube. Every and its chosen representative differ by less than on .
For any , choose with and use equicontinuity for both functions and step 2.1 to obtain .
The finitely many representatives form an -net, so is totally bounded.
Depends on
- An equicontinuous family on a compact metric space is uniformly equicontinuous
- Equicontinuity and pointwise boundedness on a compact metric space imply uniform boundedness
- Finite $\varepsilon$-net and totally bounded metric space
- The space $C(K,\mathbb{R})$ of continuous real-valued functions on a nonempty compact metric space
- Open cover, subcover, compact metric space, and compact subset of a metric space
Used by
Dependency tree · next 3 levels
Direct dependencies and their dependencies through the next three levels: 52 results over 15 levels. An arrow runs from a result to what uses it, and this result sits at the bottom with a heavier outline. Click the chart to enlarge it.
Sources
- The Ascoli--Arzelà Theorem (MIT) (standard reference, not scraped)