Unit modulo n
= Unit modulo n
A residue class modulo $n$ is a unit exactly when it is represented by an integer coprime to $n$. The units form the multiplicative group $(\mathbb Z/n\mathbb Z)^\times$.
= Unit modulo n
A residue class modulo $n$ is a unit exactly when it is represented by an integer coprime to $n$. The units form the multiplicative group $(\mathbb Z/n\mathbb Z)^\times$.