# Changes

Example 1: the Klein four group consists of the set of formal symbols $\{1, i, j, k \}$ with the relations $i^{2} =j^{2}=k^{2}=1, \; ij=k, \; jk=i, \; ki=j.$ All elements of the Klein four group (except the identity 1) have [[order]] 2. The Klein four group is [[isomorphic]] to $Z_{2}\times Z_{2}$ under mod addition.
Example 2: the set of complex numbers {1, -1, <i>i</i>,<i>-i</i>} under multiplication, where <i>i</i> is the square root of -1, the basis of the [[imaginary numbersnumber]]s. This group is [[isomorphic]] to $Z_{4}$ under mod addition.