Lemma from Zassenhaus
The following facts, which can be traced back to Hans Zassenhaus , are referred to as the Zassenhaus lemma in mathematics :
- the proposition for subnormal series of groups, also known as butterfly lemma , see series (group theory) #Lemma von Zassenhaus
- the more common Lemma von Margulis-Zassenhaus or Lemma von Margulis (also Lemma von Kazhdan-Margulis-Zassenhaus ) called auxiliary proposition for matrix groups, see Lemma von Margulis # Lemma von Margulis (group-theoretical formulation)
