Closed maps on spaces with point-countable bases
The structure of spaces which are closed images of (regular) spaces with point-countable bases is studied. The author shows that such spaces have countable \(\pi\)-character and a point-countable \(\pi\)-base and consequently topological groups of that kind are metrizable. He also obtains a theorem which is one more generalization of Lashnev's well-known theorem concerning closed mappings on metric spaces.
scientific article; zbMATH DE number 1340405