Subgroup test: Difference between revisions

Revision as of 02:27, 29 January 2014

Revision as of 02:29, 29 January 2014

Line 4:

Let <math>G

</math> be a group and let <math>H</math> be a nonempty subset of <math>G</math>. If for all <math>a</math> and <math>b</math> in <math>H</math>, b<supmath>a b ^{-1}</supmath> is in <math>H</math>, then <math>H</math> is a subgroup of <math>G</math>.

===Proof===