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.
A planar triangulation has linearly many triangles and edges
Statement
For a triangulation of the convex hull of distinct planar sites with affine dimension two, let be the number of sites on the hull boundary, the number of triangles, and the number of edges. Then In particular and .
Facts & Assumptions
Given: A finite triangulation of the convex hull of distinct sites of affine dimension two.
Planar triangulations, Delaunay structures, and Voronoi cells: every hull-boundary site is a vertex, the boundary is subdivided at all such sites, and bounded faces are exactly the chosen triangles.
Euler counting for a finite planar triangulation: and for this triangulation.
The convex hull boundary is a polygon with exactly boundary edges after subdivision at its sites.
Proof
By [F1] and [A1], the triangulation has hull boundary sites and therefore exactly subdivided hull edges. Then [F2] gives .
By [F2], . Since , the formulas imply and .
Depends on
Used by
Dependency tree · two levels
5 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
- Mark de Berg et al., Computational Geometry: Algorithms and Applications, 3rd ed., Chapter 9 (standard reference, not scraped)
- David M. Mount, CMSC 754 Computational Geometry, Lecture 13 (standard reference, not scraped)