Source: wikibot/katetov-tong-insertion-theorem
= Katětov–Tong insertion theorem
{wiki=Katětov–Tong_insertion_theorem}
The Katětov–Tong insertion theorem is a result in the field of topology, particularly in the area of set-theoretic topology. It deals with the properties of certain types of topological spaces, specifically separable metric spaces. The theorem is named after mathematicians František Katětov and David Tong.