\begin{definition}[Definition:Right Zero Divisor]
Let $\struct {R, +, \circ}$ be a ring.
A '''right zero divisor (in $R$)''' is an element $x \in R$ such that:
: $\exists y \in R^*: y \circ x = 0_R$
where $R^*$ is defined as $R \setminus \set {0_R}$.
\end{definition}