We show that three /6 vertex floodlights suffice to illuminate any triangle, and we prove that any quadrilateral can be illuminated by three /4 vertex floodlights.
Felipe Contreras, Jurek Czyzowicz, Nicolas Fraiji,...
Let S be any family of n c-oriented polygons of the two-dimensional Euclidean plane E2 , i.e., bounded intersection of halfplanes whose normal directions of edges belong to a
We give a proof of Guenin's theorem characterizing weakly bipartite graphs by not having an odd-K5 minor. The proof curtails the technical and case-checking parts of Guenin...