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.
Ext balance isomorphisms satisfy change-of-resolution cocycle laws
Statement
If denotes the balance map attached to supplied projective data and injective data , then is the identity when the comparison data are unchanged, and comparison through any intermediate resolution gives the same map as direct comparison.
Facts & Assumptions
Given: Two choices of resolution data and, where needed, a third intermediate choice.
Proof
The direct comparison and the composite through the intermediate data are morphisms of the same Ext delta functors and both restrict to the identity on degree-zero .
The Ext balance isomorphism is independent of resolution comparison data identifies these morphisms. The same argument with identical data gives the identity law, and The Ext balance isomorphism is natural in both variables makes the laws natural.
Depends on
Used by
- The balanced Ext bifunctor Definition
Dependency tree · two levels
7 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
- Charles A. Weibel, An Introduction to Homological Algebra, Chapter 2 (standard reference, not scraped)