\begin{definition}[Definition:Graph Parametrization]
Let $U \subseteq \R^n$ be an open subset of $n$-dimensional Euclidean space.
Let $f : U \to \R^k$ be a real function.
Let $\map \Gamma f$ be the graph of $f$.
Let $\gamma_f : U \to \R^n \times \R^k$ be a mapping such that:
:$\map {\gamma_f} u = \tuple {u, \map f u}$
Then $\gamma_f$ is called the '''graph parametrization (of $\map \Gamma f$)'''.
\end{definition}