Subgroup

In group theory, a branch of mathematics, given a group  under a binary operation, a subset  of  is called a subgroup of  if the elements  also forms a group under the binary operation.

The situation could arise in which the subset  does not comply with the binary operation. In that case, H would not be a subgroup.

For example, the even numbers are a subgroup of the integers, with addition as the binary operation.

Category:Group theory