projective configuration
11Levi graph — infobox graph name = Levi graph image caption = The Pappus graph, a Levi graph with 18 vertices formed from the Pappus configuration. Vertices labeled with single letters correspond to points in the configuration; vertices labeled with three… …
12Gray graph — infobox graph name = Gray graph image caption = namesake = Marion Cameron Gray vertices = 54 edges = 81 girth = 8 chromatic number = 2 chromatic index = 3 properties = Cubic Semi symmetricIn mathematics, the Gray graph is an undirected bipartite… …
13Incidence structure — In combinatorial mathematics, an incidence structure is a triple :C=(P,L,I)., where P is a set of points , L is a set of lines and I subseteq P imes L is the incidence relation. The elements of I are called flags. If :(p,ell) in I,we say that… …
14Ernst Steinitz — (June 13, 1871 – September 29 1928) was a German mathematician. Biography Steinitz was born in Laurahütte (Siemianowice Śląskie), Silesia, Germany (now in Poland), the son of Sigismund Steinitz, a Jewish coal merchant, and his wife Auguste Cohen; …
15229 (number) — 229 is the natural number between 228 and 230. It is also a prime number.Telephone Area code 229 is assigned to the area around the city of Albany in southwestern Georgia.In mathematics229 is a regular prime, a long prime, a twin prime (with 227) …
16Incidence geometry (structure) — An incidence geometry is a mathematical structure composed of objects of various types and an incidence relation between them. The number of types of object used in the structure is called the rank of the incidence geometry.Incidence geometries… …
17Geometric graph theory — In mathematics, a geometric graph is a graph in which the vertices or edges are associated with geometric objects or configurations. Geometric graph theory is a specialization of graph theory that studies geometric graphs. Notable geometric… …
18Birkhoff polytope — The Birkhoff polytope B n is the convex polytope in R N (where N = n ²) whose points are the doubly stochastic matrices, i.e., the n times; n matrices whose entries are nonnegative real numbers and whose rows and columns each add up to 1.The… …
19Nauru graph — The Nauru graph is Hamiltonian. Vertices 24 Edges 36 Radius 4 …
20Axiomes De Plans Projectifs/Suite Des Axiomes — Article principal : Axiomes de plans projectifs. La géométrie projective a permis de s abstraire des impressions intuitives de la géométrie plane euclidienne. La géométrie projective ne travaille que sur les alignements et les intersections …
