Alphabeta Math
False statementConstruction: Literature-sourcedVerification: AI-adaptedprecheck passaudited 2026-09-04 rests on unproved material (inherited)
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.

Rests on 3 statements not proved in this library, by way of the results it cites. This item cites no such statement directly; it depends on results that do. The unproved premises it inherits are Cohen's first model: an infinite Dedekind-finite set of reals, Sierpiński 1947: the generalised continuum hypothesis implies the Axiom of Choice and The continuum hypothesis and its generalisation are independent of ZFC. Each is recorded with a citation to the literature and is not established here, because the track that would prove it has not yet been developed in this library. Everything else in this proof is proved here.

FALSE: derived functors in two variables are automatically balanced

Statement

Whenever a bifunctor can be derived in each variable, the two derived constructions are automatically balanced.

Facts & Assumptions

Given: The Axiom of Dependent Choice, a field k, the ring R=k[ε]/(ε2), the abelian categories A=Vectkfd and C=R-Modfd, and the bifunctor B(A,C):=AkHomR(k,C) to Vectkfd.

[L1]

With supplied projective and injective data, one may derive an additive bifunctor in either variable and thereby obtain two candidate constructions (A bifunctor can be derived in either variable when the relevant resolution data are supplied).

[L2]

A balanced derived bifunctor relative to the supplied data requires extra natural isomorphisms, natural in both variables and normalized by the degree-zero identifications (A balanced derived bifunctor).

Refutation

technique · direct
1.1

The functor AA is exact on finite-dimensional vector spaces, CHomR(k,C) is left exact, and tensoring over k is exact. Hence B is additive and left exact in each variable in the sense required by [L1]. Give kA its length-zero projective resolution. The first-variable right-derived object at (k,k) is then zero in every positive degree.

L1givenconstructalgebra
1.2

The R-module R is injective: the coefficient-of-ε functional identifies R with Homk(R,k) as an R-module, and HomR(,Homk(R,k))Homk(,k) is exact. Thus 0k1εRεRεR is an injective resolution of k: at every copy of R, both the image and kernel of multiplication by ε are the ideal (ε).

givenconstructalgebra
2.1

Applying B(k,)=HomR(k,) to the deleted resolution in step 1.2 gives a cochain complex with one copy of k in every degree and zero differentials, since multiplication by ε annihilates HomR(k,R)(ε). Consequently the second-variable right-derived object in degree 1 is k, whereas the first-variable object from step 1.1 is 0. They cannot be isomorphic, so the balance data required by [L2] do not exist and the displayed automatic-balance claim is false.

L1L2step 1.1step 1.2algebra

Depends on

Used by

Nothing in the library uses this result yet.

Dependency tree · two levels

8 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