\begin{definition}[Definition:Projection (Mapping Theory)/Second Projection]
Let $S$ and $T$ be sets.
Let $S \times T$ be the Cartesian product of $S$ and $T$.
The '''second projection on $S \times T$''' is the mapping $\pr_2: S \times T \to T$ defined by:
:$\forall \tuple {x, y} \in S \times T: \map {\pr_2} {x, y} = y$
\end{definition}