# accumulation point

If \(X\) is a set with a topology, then an element \(p\) of \(X\) is said to be an *accumulation point* of \(X\) if every open subset of \(X\) containing \(p\) also contains elements of \(X\) distinct from \(p\).

- [MLA] “accumulation point.”
*Platonic Realms Interactive Mathematics Encyclopedia.*Platonic Realms, 19 Mar 2013. Web. 19 Mar 2013. <http://platonicrealms.com/> - [APA] accumulation point (19 Mar 2013). Retrieved 19 Mar 2013 from the
*Platonic Realms Interactive Mathematics Encyclopedia:*http://platonicrealms.com/encyclopedia/accumulation-point/