# Isotonic function

An order preserving function $LaTeX: f: X \rightarrow \mathbb{R}^m$, i.e. for any $LaTeX: x$ and $LaTeX: y$ in $LaTeX: X$
$LaTeX: x > y \Rightarrow f(x) > f(y) \; \mbox{ and } \; x < y \Rightarrow f(x) < f(y).$