Given the task definition and input, reply with output. In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

An abelian group is a set , " A " , together with an operation • that combines any two elements " a " and " b " to form another element denoted " a " • " b " .

An abelian group is a set , " A " , together with an operation " • " .