Keywords: ErdÅ‘s–Faber–Lovász conjecture.svg An instance of the ErdÅ‘s “Faber “Lovász conjecture four cliques of four vertices each any two of which intersect in a single vertex can be four-colored Own 2007-09-10 David Eppstein Graph coloring; vertex Files by User David Eppstein from en wikipedia Paul ErdÅ‘s Graphs with 11 vertices |