Alphabeta Math
ExampleConstruction: AI-generatedVerification: AI-generatedPipeline-generatedprecheck passjudge pass (gpt-6-luna)
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.

Exact range recovery on a rank-k matrix

Example

Assume Countable Choice for the finite-dimensional Gaussian probability law. Let A=diag⁡(4,1,0,0)∈R4×4, take target rank k=2, oversampling p=2, and draw Ω∈R4×4 with iid standard real Gaussian entries. The randomized range finder returns QQ∗A=A almost surely, so its spectral error is zero.

Facts & Assumptions

Given: Countable Choice for the finite Gaussian law, and the fixed diagonal matrix and the Gaussian range-finder draw.

[F1]

The algorithm returns an orthonormal basis of Ran⁡(AΩ) and then QQ∗A (Exact Gaussian randomized range finder).

[F2]

Orthogonal SVD coordinates preserve the iid Gaussian law (Orthogonal and unitary invariance of Gaussian matrix blocks).

[F3]

A wide Gaussian matrix has full row rank almost surely (A wide Gaussian matrix has full row rank almost surely).

Verification

1.1givenF2F3algebra

The displayed diagonal matrix has rank 2 and SVD A=UΣV∗ with U=V=I and Σ2=0. Write Ω1 for its first two rows. By [F2]–[F3], Ω1 has row rank 2 almost surely.

2.1step 1.1F1givenalgebra∎

For every such draw, AΩ=[40010000]Ω1 has range exactly span⁡(e1,e2), since the first two rows of Ω have rank 2 and multiplication by diag⁡(4,1) preserves rank. Thus QQ∗ is the projector onto this span and QQ∗A=A.

Depends on

Used by

Nothing in the library uses this result yet.

Dependency tree · two levels

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Sources