Solution
= Solution
The integers are closed under addition, addition is associative, zero is an identity, and $-n$ is the additive inverse of $n$. Thus $(\mathbb Z,+)$ is an <abelian group>.
= Solution
The integers are closed under addition, addition is associative, zero is an identity, and $-n$ is the additive inverse of $n$. Thus $(\mathbb Z,+)$ is an <abelian group>.