# Interior of a set

From Encyclopedia of Mathematics

* in a topological space *

The set of interior points of (cf. Interior point of a set). It is usually denoted by . Invariably, , where is the boundary of . The interior of is also equal to the union of all subsets of that are open in the entire space. The interior of a set is sometimes known as the open kernel.

**How to Cite This Entry:**

Interior of a set.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Interior_of_a_set&oldid=14280

This article was adapted from an original article by S.M. Sirota (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article