Obligatory subsystems of triple systems
The paper studies unavoidable configurations in triple systems with uncountable chromatic number, and with no two triples intersecting by 2 points. It is proved that every unavoidable subsystem is tripartite, and can be realised as the collection of rainbow-colored triangles in a finite 3-edge-colored graph. An infinite series of unavoidable systems is found.
scientific article; zbMATH DE number 5355113
scientific article