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.
The point linear solve certifier returns a sound solution ball on success
Statement
For exact stored dyadic , if Finite precision point linear solve certificate with explicit status returns certified with ball , then is invertible and its unique solution to belongs to that ball. A range-failure or inconclusive result makes no such claim.
Facts & Assumptions
Given: The exact input data and a certified return with outward bounds , , and .
The point algorithm's rounded products and residuals satisfy the stated operationwise error allowances (Finite precision point linear solve certificate with explicit status, Rounded matrix products give certified linear and normal-equation residual allowances).
Outward interval DAG evaluation encloses every exact operation and its range is isotone (Outward-rounded operations are inclusion-isotone and enclose DAG evaluations).
Usable residual data imply a unique solution within (A uniform approximate inverse and residual enclose every linear solution).
Proof
On a successful run, the columnwise rounded products enclose every column of with Euclidean errors at most , by [F1]. The Frobenius error between the rounded product matrix and is therefore at most . Outward soundness [F2] encloses , so the reported bounds by the triangle inequality and .
The rounded residual allowance bounds and the rounded product allowance bounds by [F1]. Thus , where [F2] makes each reported upper bound outward and .
These are usable point residual certificate data with . By [F3] the system has a unique solution and . The latter inequality is exactly the returned ball membership.
Depends on
- Finite precision point linear solve certificate with explicit status
- A uniform approximate inverse and residual enclose every linear solution
- Rounded matrix products give certified linear and normal-equation residual allowances
- Outward-rounded operations are inclusion-isotone and enclose DAG evaluations
Used by
- Finite-budget exact or safeguarded inexact Newton-Kleinman policy iteration Algorithm
- Finite-budget structure-preserving doubling iteration for the DARE Algorithm
- Finite Riccati candidate, Newton-Kleinman, and doubling wrappers return a status Lemma
Cited to discharge well-definedness by Finite precision point linear solve certificate with explicit status.
Dependency tree · two levels
20 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
- Siegfried M. Rump, Verification methods: Rigorous results using floating-point arithmetic, Acta Numerica 19 (2010), §10.5 (standard reference, not scraped)
- Nicholas J. Higham, Numerical Linear Algebra and Matrix Analysis, MIMS EPrint 2015.103, §1 (standard reference, not scraped)