Exterior (topology)
From Wikipedia, the free encyclopedia
In topology, the exterior of a subset S of a topological space X is the union of all open sets of X which are disjoint from S. It is itself an open set. The exterior of S is denoted by
- ext S
or
- Se.
[edit] Equivalent definitions
The exterior is equal to the complement of the topological closure of S and to the interior of the complement of S in X.
