Abstract. A circular-arc model (C, A) is a circle C together with a collection A of arcs of C. If A satisfies the Helly Property then (C, A) is a Helly circular-arc model. A (Helly...
A set of planar graphs share a simultaneous embedding if they can be drawn on the same vertex set V in the Euclidean plane without crossings between edges of the same graph. Fixed ...
We characterize bipartite Steinhaus graphs in three ways by partitioning them into four classes and we describe the color sets for each of these classes. An interesting recursion ...
Gerard J. Chang, Bhaskar DasGupta, Wayne M. Dym&ag...
A b-coloring is a coloring of the vertices of a graph such that each color class contains a vertex that has a neighbor in all other color classes, and the b-chromatic number of 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...