Every smooth manifold is assumed to be Hausdorff and second-countable. Suppose $G$ is a Lie group, $H$ is a Lie subgroup of $G$, $N$ is a closed Lie subgroup of $G$ such that $N$ is normal, $N\cap H=\{e\}$, and $NH=G$, where $NH=\{ab:a\in N, b\in H\}$. Is $H$ closed in $G$? [![enter image description here][1]][1] [1]: https://i.sstatic.net/HAmrE.jpg