🌐EnglishEnglishEspañolFrançaisItalianoPortuguêsTiếng ViệtРусскийالعربية한국어中文日本語EntityQ926996· pop 12· linked from 74 articlesfirst-countable spaceAlso known as first axiom of countabilitytopological space in which every point admits a countable neighborhood basisAvailable in 12 languagesEspañolFrançais中文日本語РусскийItalianoCatalanGalicianTiếng ViệtUkrainianConnectionssecond-countable spaceEntityorder topologyEntityCategoriesGeneral topologyProperties of topological spaces