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.
Why the unrestricted complete-metric Baire theorem would overstate the choice cost here
Remark
The proof of A Banach space has no countably infinite Hamel basis does not need the full statement "every complete metric space is Baire". It only needs the separable complete-metric route, and that is exactly the distinction recorded in The Baire category theorem is four inequivalent statements over ZF ‡: over ZF, the separable theorem is choice free, whereas the unrestricted complete-metric theorem is equivalent to Dependent Choice.
That matters here because the countable Hamel basis already supplies an explicit countable dense set, namely the rational span of the basis. Using the sharper argument records the actual cost of the theorem proved on this page. Invoking the unrestricted theorem would still yield a correct proof of the Banach-space claim, but it would advertise a stronger choice principle than the written argument spends.
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
10 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
- Paul Howard and Eleftherios Tachtsis, On infinite-dimensional Banach spaces and weak forms of the axiom of choice (standard reference, not scraped)