KnowraUrysohn's metrization theoremLinked fromLinked fromThe 5 pages that link to Urysohn's metrization theorem, each with the reason it gives.All 5Related 2Compared with 3Separation axiomRelated: Regularity and Hausdorffness are central hypotheses for recognizing metrizable spaces.Urysohn's lemmaCompared with: This separate theorem uses related separation ideas but concludes metrizability, not a single separator.Tietze extension theoremCompared with: It is another major theorem about normal spaces, but concerns metrization rather than function extension.Lindelöf's lemmaRelated: The lemma helps connect countable bases with metrization arguments.Nagata–Smirnov metrization theoremCompared with: It replaces a σ-locally finite base with the stronger-looking requirement of a countable base.