Example 5.2.3. Standard Dice Pairs.
When gambling with a pair of dice, one might use S=ordered pairs of all possible rolls. Then
\begin{equation*}
S = \text{ {(a,b): a=die 1 outcome, b=die 2 outcome}}.
\end{equation*}
Choose
\begin{equation*}
X( (a,b) ) = a+b.
\end{equation*}
Then, \(R\) = {2, 3, 4, 5, ..., 12}.