17 Answers votes newest views recent 8Labelled spanning trees without edge crossings 6coordinates of vertices of regular simplex 5Ordered geometries from convex subsets of the plane 4What are the Applications of Hypergraphs 10Continuous automorphism groups of normed vector spaces? 5Combinatorial distance ≡ Euclidean distance 3Is the theory of incidence geometry complete? 2Origins of Mathematical Symbols/Names 18How much choice is needed to show that formally real fields can be ordered? 5Nice proof of the Jordan curve theorem? 5Chromatic number of graphs of tangent closed balls 2How many of the true sentences are provable? 5Generalizations of Planar Graphs 11Extremal question on matrices 5Combinatorial results without known combinatorial proofs 5Which graphs have incidence matrices of full rank? 6Erdős–Stone theorem type edge density estimates for bipartite graphs?