Topic: Topology (Undergraduate)

The First Uncountable Ordinal and Cofinal Neighborhoods

The Fixed-Point Sign Test on an Interval

The Finite-Intersection Method for Compactness

The Exponential Law For Compact-Open Function Spaces

The Extreme Value Theorem For Metric Spaces

The Discrete Metric Induces the Discrete Topology

The Discrete Topology

The Discrete and Indiscrete Topologies as Extremes

The Discrete Metric and Its Unusual Balls

The Diagonal Is Closed Exactly in Hausdorff Spaces