On bounding the chromatic number of L-graphs Original Research Article

We show that the intersection graph of a collection of subsets of the plane, where each subset forms an “L” shape whose vertical stem is infinite, has its chromatic number χ bounded by a function of the order of its largest clique ω, where it is shown that χ⩽2(143)(4ω−1−1). This proves a special case of a conjecture of Gyàrfàs and Lehel.