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DefinitionDefinition: AI-adaptedProof: AI-generatedPipeline-generated
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.

Tensor products of finitely many linear maps

Definition

For a finite ordered family of finite-dimensional complex vector spaces Hk,Kk and complex-linear maps Tk:Hk→Kk, the tensor map ⨂k<nTk:H0⊗⋯⊗Hn−1→K0⊗⋯⊗Kn−1 is the unique linear map satisfying

(⨂k<nTk)(x0⊗⋯⊗xn−1)=T0x0⊗⋯⊗Tn−1xn−1.

For n=0, the tensor map is the identity map z↦z on the empty tensor product C.

Facts & Assumptions

Given: A finite ordered family of complex vector spaces and linear maps Tk:Hk→Kk.

[F1]

A binary algebraic tensor product is generated by elementary tensors, and a tensor with a zero factor vector is zero (The tensor product M⊗RN from the additive group underlying the free Z-module on M×N, elementary tensors, and finite tensor sums). Over C, tensoring is complex-linear in each factor (Over a commutative ring, M⊗RN is an R-module with r(m⊗n)=(rm)⊗n=m⊗(rn)).

[F2]

A finite iterated tensor product represents multilinear maps, including the empty and one-factor cases (Finite iterated tensor products represent multilinear maps independently of parenthesization).

[F3]

Each Tk is linear on its factor (Linear map between vector spaces over the same field).

Proof

1.1givenF1F3algebra

For n=0, the prescribed map is the identity on C. For n>0, the function (x0,…,xn−1)↦T0x0⊗⋯⊗Tn−1xn−1 is linear in each argument: replacing any xk by axk+byk replaces its image by aTkxk+bTkyk by [F3], and tensoring is linear in that factor.

2.1step 1.1F1F2algebra∎

For n>0, [F2] gives a unique linear extension of the multilinear function in step 1.1, hence the map in the Definition. Repeated use of [F1] shows that elementary tensors span any nonempty iterated tensor product. If some Hk=0, every source elementary tensor is zero by [F1], so the domain is zero and the unique linear map from it is zero. If some Kk=0, the same argument makes the codomain zero, and the unique linear map to it is zero. In either case the displayed rule holds. For n=0, the empty elementary tensor is 1∈C by [F2]; its prescribed image is 1, which uniquely determines the identity linear map.

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