section_path: In finite geometry
section_name: In finite geometry
paragraph_text: In finite geometry
  
  Many ideas of dimension can be tested with finite geometry. The simplest instance is PG(3,2), which has Fano planes as its 2-dimensional subspaces. It is an instance of Galois geometry, a study of projective geometry using finite fields. Thus, for any Galois field GF(q), there is a projective space PG(3, q) of three dimensions. For example, any three skew lines in PG(3, q) are contained in exactly one regulus.