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.
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- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
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These labels describe origin, not correctness: citations and verification chips remain separate evidence.
An interval determinant excluding zero certifies nonsingularity and sign
Statement
Let and let be a nonempty family of real matrices. Suppose a real interval contains for every . If , then every is nonsingular; if is positive or negative, its sign is the common determinant sign. If , every member is singular. When neither condition holds, the certificate makes no singularity or sign assertion.
Facts & Assumptions
Given: and a sound real interval determinant enclosure as stated.
The determinant is the finite Leibniz sum for a real square matrix (For , the determinant over a commutative ring by the Leibniz formula, and for a real matrix).
A finite square real matrix is invertible exactly when its determinant is nonzero (A finite square real matrix is invertible if and only if its determinant is nonzero).
Proof
For any , the assumed enclosure gives . If , then , and [F2] makes nonsingular. If is a positive or negative interval, every has its corresponding sign.
If , then for every , so [F2] makes every member singular. In the remaining case the stated output is inconclusive and no singularity or sign claim is made.
Depends on
Used by
Dependency tree · two levels
17 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), §10.10 (standard reference, not scraped)