🌐EnglishEnglishDeutschРусский한국어EntityQ7511782· pop 5· linked from 6 articlessieveconcept used in defining a Grothendieck topology; generalization of the collection of open subsets of an open setAvailable in 5 languagesDeutschРусскийGreek한국어via Wikidata sitelinks · CC0ConnectionsmathematicsEntityInternational Standard Book NumberEntityCategoriesCategory theory