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.
TwoProduct product and residual computation using fused multiply-add
Definition
For real floating-point a,b compute p=fl(ab), then e=fma(a,b,-p). Return range-failure if the product overflows, the exact FMA residual is nonzero subnormal or overflow, or another operationwise range condition fails; otherwise return (p,e).
Remarks
The separate Finite arithmetic schedules terminate, with early failure counted separately applies to the ordered multiplication and FMA, each returning a finite result or immediate range failure. It gives at most two attempted rounded operations and exactly two on success. Exact recovery under representability of the residual as zero or a normal number is proved in TwoProduct with fused multiply-add returns the exact product residual.
Depends on
Used by
Dependency tree · two levels
3 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
- Fundamentals of Numerical Computation, floating-point arithmetic (standard reference, not scraped)
- Higham, The Accuracy of Floating Point Summation (standard reference, not scraped)
- Ogita, Rump, and Oishi, Accurate Sum and Dot Product (standard reference, not scraped)