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.
Certified geometric predicate for interval-valued coordinates
Definition
Input: finite closed dyadic intervals for all coordinates in one orientation,
incircle, or insphere determinant. Output: positive, negative, or
indeterminate. Construct the orientation or lifted matrix as in
Dyadic orientation and lifted sphere determinants. For a lifted matrix, form
each squared-norm entry by squaring its coordinate intervals and adding the
results from coordinate index through from left to right, using the
outward interval operations of
Outward-rounded interval, rectangle and ball operations. If matrix construction
returns a nonfinite status, return indeterminate.
Enumerate the permutations in lexicographic tuple order. For each permutation,
start with and multiply the selected row-entry intervals from row
through row , from left to right, using outward interval multiplication.
For an odd permutation, replace the product by using outward
interval subtraction. Initialize the determinant interval with the first
signed term, then add each later signed term from left to right using outward
interval addition. If any operation returns a nonfinite status, return
indeterminate. For a finite , return positive when ,
negative when , and indeterminate when . This procedure
reports a uniform raw determinant sign over the represented coordinate box;
it does not choose a center point or invoke exact point fallback.
Depends on
Used by
Dependency tree · two levels
11 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
- CGAL Developer Manual, Robustness Issues, §11.1 (standard reference, not scraped)
- Mark de Berg et al., Computational Geometry: Algorithms and Applications, 2nd ed., §1.2 (standard reference, not scraped)