🌐EnglishEnglishEspañolPolski中文EntityQ985704· pop 8· linked from 4 articleshorizontal line testtest for the bijectivity of a functionAvailable in 8 languagesEspañol中文CatalanPolskiRomanianTamilUrduvia Wikidata sitelinks · CC0ConnectionsmathematicsEntityInternational Standard Book NumberEntityCategoriesBasic concepts in set theory