Jan 1, 0001
Separation axiom
Let $(X, \tau)$ - a topological-space.
- First: $\forall x,y \in X:,\exists U(x), V(y) \in \tau \hookrightarrow x \not\in V(y),,,y \not\in U(x)$
- Second (Hausdorff): $\forall x,y \in X:,\exists U(x), V(y) \in \tau \hookrightarrow U(x) \cap V(y) = \varnothing$