point countable base
Let be a topological space. A basis of is a point countable base if every point of is contained in at most countably many sets of .
Any uniform base is a point countable base, and a theorem of R. W. Heath states that every semimetric space with a point countable base is developable.
References
- 1 Steen, Lynn Arthur and Seebach, J. Arthur, Counterexamples in Topology, Dover Books, 1995.