T0-spaces
A T0-space is a topological space X = (X,Ω(X)) such that
for every pair of distinct points in the space, there is an open set containing one but not the other: x,y ∈ X ⇒ ∃U ∈ Ω(X)[(x ∈ U and y ∉ U) or (y ∈ U and x ∉ U)].
Let X and Y be T0-spaces. A morphism from X to Y is a function f : X→Y that is continuous: V ∈ Ω(Y) ⇒ f−1[V] ∈ Ω(X).
| Classtype | second-order |
| Amalgamation property | yes |
| Strong amalgamation property | no |
| Epimorphisms are surjective | no |
Remark: The properties given above use an (E,M) factorization system with E = surjective morphisms and M = embeddings.
http://www.wikipedia.org/wiki/Topology_glossary