ryamadaのコンピュータ・数学メモ

Combinatorial Geometry

幾何組み合わせ組み合わせ幾何射影平面

組み合わせ幾何についてのこちらの文書によれば

- Incidence Structure
  - An incidence structure is a triple $(V, B, ∼)$ so that $V, B$ are disjoint sets and $∼$ is a relation on $V \times B$ .
  - We call elements of $V$ points, elements of $B$ blocks or lines and we associate each line with the set of points incident with it.
  - So, if $p \in V$ and $b \in B$ satisfy p ∼ b we say that p is contained in b and write $p \in b$ and if $b, b' \in B$ we let $b \cap b' = \{p \in P : p ∼ b, p ∼ b'\}$