🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPolskiPortuguêsSvenskaTiếng ViệtРусскийفارسی한국어中文日本語EntityQ810214· pop 25· linked from 135 articlesbaseAlso known as topological basis, topological base, basiscollection of open sets that is sufficient for defining a topologyAvailable in 25 languagesEspañolFrançaisDeutsch中文日本語РусскийPortuguêsItalianoCatalanCroatianCzechConnectionsneighborhood systemEntitycontinuous functionEntityCategoriesGeneral topology