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.
Stone's theorem, under choice: every metric space is paracompact
Statement
Assume the Axiom of Choice. Every metric space is paracompact.
Facts & Assumptions
Given: The Axiom of Choice, a metric space , and an arbitrary open cover of its metric topology.
Under choice, every metric open cover has a point-finite open refinement, and Ornstein's second construction turns that point-finite cover into a locally finite open refinement (Under choice, every open cover of a metric space has a point-finite open refinement, Under choice, Ornstein's second construction turns a point-finite metric open cover into a locally finite open refinement).
Paracompactness means that every open cover has such a refinement (Paracompactness: every open cover has a locally finite open refinement, with no separation axiom built into the word).
Proof
Apply [L1] to the arbitrary cover .
The resulting locally finite open refinement is exactly the condition in [F1], so is paracompact.
Remarks
The theorem is proved here with the Axiom of Choice as a sufficient hypothesis. No assertion is made that this is its exact set-theoretic strength.
Depends on
Under choice, every open cover of a metric space has a point-finite open refinement
Under choice, Ornstein's second construction turns a point-finite metric open cover into a locally finite open refinement
Paracompactness: every open cover has a locally finite open refinement, with no separation axiom built into the word
Metric space: iff , symmetry, and the triangle inequality; pseudometric and ultrametric
The Axiom of Choice