\begin{definition}[Definition:Homogeneous Function/Real Space/Zero Degree]
Let $f: \R^2 \to \R$ be a real-valued function of two variables.
$\map f {x, y}$ is a '''homogeneous function of degree zero''' or '''of zero degree''' {{iff}}:
:$\forall t \in \R: \map f {t x, t y} = t^0 \map f {x, y} = \map f {x, y}$
Category:Definitions/Homogeneous Functions
\end{definition}