Sets of $r$-graphs that color all $r$-graphs

Yulai Ma, Davide Mattiolo, Eckhard Steffen +1

An $r$-regular graph is an $r$-graph, if every odd set of vertices is connected to its complement by at least $r$ edges. Let $G$ and $H$ be $r$-graphs. An $H$-coloring of $G$ is a…