Wir betrachten das Vektorfeld

${\displaystyle f\colon \mathbb {R} \times \mathbb {R} ^{2}\longrightarrow \mathbb {R} ^{2},\,(t,u,v)\longmapsto (t^{2}uv,u^{2}-tv^{2}).}$

${\displaystyle {}t\in \mathbb {R} }$

${\displaystyle f_{t}\colon \mathbb {R} ^{2}\longrightarrow \mathbb {R} ^{2},\,(u,v)\longmapsto (t^{2}uv,u^{2}-tv^{2}).}$