Separation axioms

Normal space

A normal space is a topological space (𝑋,T) such that any two disjoint closed subsets 𝐴,𝐵 ⊆𝑋 have disjoint open neighbourhoods 𝑈,𝑉 ∈T, #m/def/topology i.e. 𝐴 ⊆𝑈 ∈T and 𝐵 ⊆𝑉 ∈T. A T4-space is one which is both normal and Hausdorff. #m/def/topology

Properties

• Hausdorff-compact implies normal

#state/develop | #lang/en | #SemBr