Alexander's subbase theorem

Alexander's subbase theorem

[‚al·ig′zan·dərz ¦səb‚bās ‚thir·əm]
(mathematics)
The theorem that a topological space is compact if and only if its topology has a subbase with the property that any set that is contained in the union of a collection of members of the subbase is contained in the union of a finite number of members of this collection.
Full browser ?