Topic: Regular and Normal Spaces

The Sorgenfrey Plane Is Not Normal

The Sorgenfrey Line Is Normal

The Moore Plane Is Regular but Not Normal

The Deleted Tychonoff Plank

T3 and T4 Conventions and Implications

Separation-Axiom Pitfalls in Subspaces and Products

Separating Points from Closed Sets

Separating Closed Sets in Metric Spaces

Regular Spaces and the T3 Axiom

Regularity Passes to Subspaces