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.
Euler–Heun embedded Runge–Kutta pair
Definition
For , take the shared explicit stages The Euler member is and the Heun explicit trapezoidal member is . Their embedded difference is . The local orders are proved separately. In Embedded Runge–Kutta pair and difference estimator notation, the common tableau has , , high weights and low weights .
Depends on
Used by
- Quadratic continuous extension for Heun's method Definition
- A fast-decay test problem is rejected at the minimum step Example
- A tolerance below roundoff can pass with a zero embedded difference Example
- The leading Euler–Heun estimator coefficient can vanish Example
- A nonzero leading defect makes the embedded difference asymptotically match the low-order defect Proposition
- Heun's quadratic dense output has local order two Theorem
- Local orders and leading estimator term for the Euler–Heun pair Theorem
Dependency tree · two levels
4 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
- Ernst Hairer, course notes, Chapter III: Équations Différentielles Ordinaires, §III.2 (standard reference, not scraped)
- Tobin A. Driscoll and Richard J. Braun, Fundamentals of Numerical Computation, Chapter 6 (standard reference, not scraped)