\begin{definition}[Definition:Product of Cardinals]
Let $A$ and $B$ be sets.
Let $\mathbf a$ and $\mathbf b$ be the cardinals associated respectively with $A$ and $B$.
Then the '''product''' of $\mathbf a$ and $\mathbf b$ is defined as:
:$\mathbf a \mathbf b := \map \Card {A \times B}$
where:
:$A \times B$ denotes the Cartesian product of $A$ and $B$
:$\map \Card {A \times B}$ denotes the cardinal associated with $A \times B$.
\end{definition}