This article is rated C-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Mathematics This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MathematicsWikipedia:WikiProject MathematicsTemplate:WikiProject Mathematicsmathematics articles ??? This article has not yet received a rating on the project's priority scale.

I added a citation needed for the last property, because the article explains the ${\displaystyle \operatorname {CAT} (k)}$ property and introduces it by using the categorization by Alexandrov. I couldn't find a source for the mentioned Classification by Lott-Villani-Sturm. Kellertuer ( talk) 10:11, 12 December 2013 (UTC) reply