Example image of eyePlorer eyePlorer map for 'Wolfgang Haken': 1928 3-manifold Berlin Germany June 21 Mathematician Topology Four color theorem Kenneth Appel University of Illinois at Urbana-Champaign Haken manifold Hellmuth Kneser Normal surface Computational topology Exponential growth Propositional formula Resolution (logic) Tautology (logic) Continuum (instrument) Heawood number Five color theorem Fulkerson Prize Unknotting problem Heinrich Heesch Discrete mathematics William Thurston Graph theory Haken Graph coloring History of knot theory Knot theory Unsolved problems in mathematics Poincaré conjecture Heegaard splitting Timeline of mathematics History of mathematics