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.
Cartan-Eilenberg only resolves terms
Statement
Compatible injective resolutions of the terms of a complex suffice to be a Cartan–Eilenberg resolution.
Facts & Assumptions
Given: We use abelian groups and assume AC for divisible injectivity.
Cartan–Eilenberg data also resolve cycles, boundaries and cohomology, with split horizontal exact sequences (Cartan-Eilenberg injective resolution of a bounded-below complex).
These split sequences and the cohomology resolutions identify the second hypercohomology page (Second hypercohomology spectral sequence).
Divisible groups are injective under AC; injectivity means extending along every monomorphism (Over a PID, injective modules are exactly divisible modules, Injective object).
Refutation
Take , , the quotient map, zero elsewhere. Both terms are divisible, hence injective by F3. Set and for , with horizontal differential , vertical differential zero and identity augmentation. Each column is an injective resolution of the corresponding term, and all squares commute.
But horizontal . This is not injective: the identity map on the subgroup cannot extend to , since has no integer solution. Thus the induced cycle and cohomology columns are not injective resolutions. Also cannot split, since a splitting would retract onto and give the same impossible extension. F1 therefore excludes these termwise data. F2 needs exactly the missing clauses to compute ; commuting term resolutions alone do not provide that computation. The example is bounded, has only one resolution row, and uses AC only for the two divisible terms.
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
19 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
- Sharifi, Definition 4.3.1 (standard reference, not scraped)