🌐EnglishEnglishDeutschEspañolFrançaisPortuguês中文日本語EntityQ3062521· pop 6· linked from 29 articlesHNN extensionbasic construction of combinatorial group theoryWikidata factsNamed afterHanna Neumannvia Wikidata · CC0Connectionspresentation of a groupEntitysubgroupEntityCategoriesCombinatorics on wordsGroup theory