\begin{definition}[Definition:Product Notation (Algebra)/Multiplicand]
Let $\struct {S, \times}$ be an algebraic structure where $\times$ is an operation derived from, or arising from, the multiplication operation on the natural numbers.
Let $\set {a_1, a_2, \ldots, a_n} \subseteq S$ be a set of elements of $S$.
Let:
:$\ds \sum_{\map R j} a_j$
be an instance of a composite on $\set {a_1, a_2, \ldots, a_n}$.
The set of elements $\set {a_j \in S: 1 \le j \le n, \map R j}$ is called the '''multiplicand'''.
\end{definition}