# Boundary

From Encyclopedia of Mathematics

The boundary of a subspace of a given topological space is the set of points such that every neighbourhood of any point of it contains both points from and points from . The accepted notations include , , .

A synonym for the border of a manifold, such as the border of a simplex.

**How to Cite This Entry:**

Boundary.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Boundary&oldid=15128

This article was adapted from an original article by A.V. Chernavskii (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article