Definition:Ring (Abstract Algebra)/Ring Less Zero

Definition
Let $\struct {R, *, \circ}$ be a ring. It is convenient to have a symbol for $R \setminus \set 0$, that is, the set of all elements of the ring without the zero. Thus we usually use:


 * $R_{\ne 0} = R \setminus \set 0$

Also denoted as
Most sources use $R^*$.

However, this is also uses by some sources to mean the group of units of a ring $R$.