Topology pdf

[Real Analysis] Definition of relatively open set · Each set in the subspace topology is actually...

A subset of a topological space is relatively open if it is an open set in some relative topology...

Being open relative to X means that there is some open set O′ such that O=O′∩X, and equivalently ...

In a metric space—that is, when a distance function is defined—open sets are the sets that, with ...