# closure

### Topology

The closure of a given set in a topological space is the smallest closed set containing the given set.

### Abstract Algebra

If \(F\) is a field, the *algebraic closure* of \(F\) is a field \(G\) containing \(F\) such that every polynomial with coefficients in \(F\) has a root in \(G\).

- [MLA] “closure.”
*Platonic Realms Interactive Mathematics Encyclopedia.*Platonic Realms, 25 Mar 2013. Web. 25 Mar 2013. <http://platonicrealms.com/> - [APA] closure (25 Mar 2013). Retrieved 25 Mar 2013 from the
*Platonic Realms Interactive Mathematics Encyclopedia:*http://platonicrealms.com/encyclopedia/closure/