(Q1259814)
Statements
Identifiers
Sitelinks
Wikipedia(5 entries)
- dewiki Satz von Nielsen-Schreier
- enwiki Nielsen–Schreier theorem
- frwiki Théorème de Nielsen-Schreier
- hewiki משפט נילסן-שרייר
- ptwiki Teorema de Nielsen–Schreier
theorem that every subgroup of a free group is itself free