Definition:Group of Units

Definition
Let $\left({R, +, \circ}\right)$ be a ring with unity.

Then the set $U_R$ of units of $\left({R, +, \circ}\right)$ is called the group of units of $\left({R, +, \circ}\right)$.

This can be denoted explicitly as $\left({U_R, \circ}\right)$.

Also denoted as
The group of units of a ring with unity $R$ is also seen denoted as $R^\times$, or explicitly as $\left({R^\times, \circ}\right)$.

Also see

 * Group of Units is Group