🌐EnglishEnglishDeutschEspañolFrançaisItalianoPolskiPortuguêsРусскийالعربيةفارسی中文日本語EntityQ246506· pop 17· linked from 57 articlesfield of setsmathematical structure of sets in an abstract spaceAvailable in 17 languagesFrançaisDeutsch中文日本語РусскийItalianoBanglaBelarusianCroatianFilipinoConnectionstopological spaceEntitycountable setEntityCategoriesBoolean algebraFamilies of sets