Proto-metrisable spaces are elastic
The authors introduce various notions of extendable pair-bases and prove, among other results, the following: (1) A space is proto-metrizable if and only if it has a unitary point extendable pair-base and hence proto-metrizable spaces are elastic. (2) Stratifiable spaces have weakly point extendable pair bases. (3) The class of spaces with weakly point extendable pair-bases is closed under the scattering process, and every space with a weakly point extendable pair-base is elastic.
scientific article; zbMATH DE number 1054144
scientific article