Normal subgroup
This is the current revision of Normal subgroup as edited by CSGuy (talk | contribs) at 02:36, December 18, 2008. This URL is a permanent link to this version of this page.
A subgroup N of a group G is a normal subgroup (written <math>N \triangleleft G</math>) if one of the following equivalent conditions holds:
- <math>a N = N a </math> for all <math> a \in G</math>
- <math>a N a^{-1} \subset N </math> for all <math> a \in G</math>
- <math>a N a^{-1} = N </math> for all <math> a \in G</math>