# Changes

## Klein four-group

, 16:48, 27 August 2009
Definition
* It is the group comprising the elements $(\pm 1, \pm 1)$ under coordinate-wise multiplication
* It is the unique non-cyclic group of order 4
* It is the subgroup of [[symmetric group:S4|the symmetric group on 4 elementsof degre four]] comprising the double transpositions, and the identity element.* It is the [[Burnside group]] $B(2,2)$: the ''free group'' on two generators with exponent two.
===Multiplication table===