Definition:Ringoid (Abstract Algebra)

Definition
A ringoid is an triple $\left({S, *, \circ}\right)$ where:
 * $S$ is a set
 * $*$ and $\circ$ are binary operations on $S$
 * the operation $\circ$ distributes over $*$.

That is:


 * $\forall a, b, c \in S: a \circ \left({b * c}\right) = \left({a \circ b}\right) * \left({a \circ c}\right)$
 * $\forall a, b, c \in S: \left({a * b}\right) \circ c = \left({a \circ c}\right) * \left({b \circ c}\right)$

Note that in a ringoid, there is no insistence that $S$ is closed under either of these operations, neither does $\circ$ have to be associative.

In the denotation of this structure, $\left({S, *, \circ}\right)$, the distributor is shown after the distributand.

In the context of a ringoid, the fact that $\circ$ distributes over $*$ is known as the distributive law.