About this article
Published Online: Feb 02, 2013
Page range: 235 - 237
DOI: https://doi.org/10.2478/v10037-012-0028-7
This content is open access.
In this article we prove the friendship theorem according to the article [1], which states that if a group of people has the property that any pair of persons have exactly one common friend, then there is a universal friend, i.e. a person who is a friend of every other person in the group