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.
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These labels describe origin, not correctness: citations and verification chips remain separate evidence.
The Tor balance isomorphism is natural and coherent under a change of resolutions
Statement
The balance isomorphisms for Tor commute with maps of modules and with replacement of either projective resolution.
Proof
Given: comparison maps between two resolutions of and of , and the tensor double complexes they induce.
Each comparison map gives a morphism between the two tensor double complexes, compatible with both augmented edges.
The two edge-to-total quasi-isomorphisms therefore form a commutative square on homology, so the balance isomorphism commutes with the comparison maps.
Comparison maps are unique up to chain homotopy, and homotopic maps induce the same homology map; successive changes compose coherently.
Depends on
Used by
- The balanced Tor bifunctor Definition
Dependency tree · two levels
13 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 (standard reference, not scraped)