\begin{definition}[Definition:Normal Family]
Let $X = \struct {M_1, d_1}$ and $Y = \struct {M_2, d_2}$ be complete metric spaces.
Let $\FF = \family {f_i}_{i \mathop \in I}$ be a family of continuous mappings $f_i: X \to Y$.
Then $\FF$ is a '''normal family''' {{iff}}:
:every sequence of mappings in $\FF$ contains a subsequence which converges uniformly on compact subsets of $X$ to a continuous function $f: X \to Y$.
\end{definition}