Topic: Topologies and Open Sets

The Cofinite Topology

The Axioms Defining a Topology

Testing Topology Inclusions with Open Sets

Recognizing Open Sets on the Real Line Locally

Proof That Metric Open Sets Form a Topology

Pointwise Local Bounds for Metric Comparisons

Global Metric Bounds and Equal Topologies

Finer and Coarser Topologies

Euclidean, Taxicab, and Sup Metrics Give the Same Topology

Enumerating Topologies on a Two-Point Set