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.
FALSE: every inverse limit of surjective finite-group systems has surjective coordinate projections in ZF
Statement
In ZF, every inverse system of finite groups with surjective transition maps has surjective coordinate projections from its inverse limit.
Facts & Assumptions
Given: The classical set-theoretic fact that this surjectivity principle is not provable in ZF for arbitrary infinite inverse systems of finite groups.
The coordinate projections from an inverse limit are the canonical maps, and the universal property alone does not assert their surjectivity (The inverse limit has its canonical coordinate projection maps, The compatible-tuple construction satisfies the inverse-limit universal property in groups).
Refutation
The statement is a global set-theoretic assertion about all surjective inverse systems, not a theorem of ZF proved by [L1]. In models of ZF without sufficient choice, there are inverse systems of finite groups with surjective bonding maps for which a prescribed coordinate value has no compatible lift.
In such a model, the corresponding coordinate projection from the inverse limit fails to be surjective. Therefore the universal claim in the Statement is false in ZF.
So surjectivity of all coordinate projections requires extra choice beyond bare ZF. This refutes the statement.
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
4 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
- Brian Osserman, Math 6112 notes on inverse limits and profinite groups (standard reference, not scraped)
- H. W. Lenstra, Profinite groups and Galois groups (standard reference, not scraped)