Topic: Topology (Undergraduate)

The Klein Bottle Group from Polygon Gluing

The Klein Bottle from a Paired Square

The K-Topology From Deleted Sequences

The Irrational Numbers Are Uncountable

The Intermediate Value Theorem from Connectedness

The Interior Operator Laws

The Indiscrete Topology

The Homotopy Lifting Property

The Hilbert Cube as a Countable Product

The Hawaiian Earring Is Not Semilocally Simply Connected