- topology on a set
- topology generated by a base (a family of subsets closed under finite intersections)
- examples
- trivial topology
- discrete topology
- definition of a continuous map (inverse image preserves opens)
- identity map is continuous
- constant map is continuous
- composition of continuous maps is continuous
- every map from space with discrete topology is continuous
- every map to space with indiscrete topology is continuous
- definition of a homeomorphism
- identity map is a homeomorphism
- compositions of homeomorphism is homeomorphism
- inverse of homeomorphism is homeomorphism
- Topological properties: T₀, T₁, T₂, regular
- Cantor space ℂ (the set ℕ → {⊤, ⊥} with product topology)
- ℂ is Kolmogorov