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.
Tor is not symmetric as a typed expression over every noncommutative ring
Statement
False claim: Tor is a symmetric bifunctor of two left modules over every ring.
Refutation
Given: a noncommutative ring and two left modules.
The ordinary tensor product already requires one factor to be right-handed.
Thus the supposed inputs of the symmetric expression are not generally a valid domain for Tor.
Commutativity supplies an identification of left and right actions; without it the asserted symmetry is ill-typed, not a theorem.
Depends on
Used by
Nothing in the library uses this result yet.
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 (standard reference, not scraped)