Last modified on August 22, 2010, at 04:03

König's lemma

König's lemma (also spelled Koenig's lemma to avoid the trema) is a result in Zermelo-Fraenkel Set Theory and Graph Theory. It states that an infinite tree with finitely many branching degrees must have an infinite branch. Set theorists consider this to be an important transfinite generalization of the Pigeonhole Principle.

See also

Königsberg Bridges Problem