MathOverflow is a question and answer site for professional mathematicians. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Possible Duplicate:
Commutator subgroup does not consist only of commutators?

I am looking for an simple example (i.e. for undergraduate students) of group whose commutators $xyx^{-1}y^{-1}$ do not form a subgroup.

share|cite|improve this question

marked as duplicate by HJRW, Mark Sapir, Chris Godsil, Tony Huynh, Richard Kent Jan 11 '12 at 12:54

This question was marked as an exact duplicate of an existing question.

I'm voting to close this as a duplicate of this question:… . – HJRW Jan 11 '12 at 12:40