Space S000011
Excluded Point Topology on a Three-Point Set
Also known as: Finite Excluded Point Topology
Let be a finite set with three elements. A set is closed in this topology if it contains the particular point or is empty. A set is open if it does not contain or is the whole space.
Defined as counterexample #13 ("Finite Excluded Point Topology") in DOI 10.1007/978-1-4612-6290-9.