Talk:Half graph

Graphs with uncountable chromatic number
The quoted paper of Erdös does not quote a paper by Hajnal, but a result of Hajnal and Komjáth (Hajnal, A. & Komjáth, P. Combinatorica (1984) 4: 47. https://doi.org/10.1007/BF02579156) where it is proved that a graph with uncountable chromatic number contains a half-graph on integers together with a vertex adjacent to all the vertices of this half-graph with infinite degree. pom (talk) 22:02, 14 February 2020 (UTC)