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 , take target rank , oversampling , and draw with iid standard real Gaussian entries. The randomized range finder returns 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.
The algorithm returns an orthonormal basis of and then (Exact Gaussian randomized range finder).
Orthogonal SVD coordinates preserve the iid Gaussian law (Orthogonal and unitary invariance of Gaussian matrix blocks).
A wide Gaussian matrix has full row rank almost surely (A wide Gaussian matrix has full row rank almost surely).
Verification
The displayed diagonal matrix has rank and SVD with and . Write for its first two rows. By [F2]–[F3], has row rank almost surely.
For every such draw, has range exactly , since the first two rows of have rank and multiplication by preserves rank. Thus is the projector onto this span and .
Depends on
- Exact Gaussian randomized range finder
- Orthogonal and unitary invariance of Gaussian matrix blocks
- A wide Gaussian matrix has full row rank almost surely
- Every linear map between finite-dimensional real or complex inner product spaces admits a singular value decomposition
- The Axiom of Countable Choice ($\mathrm{AC}_\omega$)
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
19 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
- Halko, Martinsson, and Tropp, Finding Structure with Randomness, §10.2 (standard reference, not scraped)
- Martinsson and Tropp, Randomized Numerical Linear Algebra: Foundations & Algorithms, §11.4.2 (standard reference, not scraped)