🌐EnglishEnglishDeutschEspañolFrançaisItalianoPolskiPortuguêsTiếng ViệtРусский中文日本語EntityQ7168101· pop 14· linked from 29 articlesperfect setsubset of a topological space that is closed and has no isolated pointsAvailable in 14 languagesEspañolFrançaisDeutsch中文日本語РусскийPortuguêsItalianoCatalanChuvashPolskiConnectionsInternational Standard Book NumberEntityGeorg CantorEntityCategoriesProperties of topological spacesTopology