de Bruijn-Erdős theorem

English

Etymology

Named after the mathematicians Nicolaas Govert de Bruijn and Paul Erdős.

Proper noun

de Bruijn-Erdős theorem

1. (graph theory) A theorem stating that, when all finite subgraphs of an infinite graph can be colored using c colors, the same is true for the parent graph.
2. (geometry) A theorem that states a lower bound on the number of lines determined by n points in a projective plane.